4:20 p.m. UPDATE:
American Muslim leaders are condemning the attack on a gay nightclub in Orlando that killed 50 people and wounded more than 50 others.
Nihad Awad, the executive director of the Council on American-Islamic Relations, called the killings a hate crime and said the group has no tolerance for extremism of any kind.
A law enforcement official has said the gunman, Omar Mateen, called 911 from the nightclub and expressed allegiance to an Islamic State leader.
Awad says members of the LGBT community have stood with Muslims in the past and today they stand that community.
3:50 p.m. UPDATE:
The Orlando mayor says of the 50 victims who died from the shooting at a gay nightclub, 39 were killed at the club and 11 people died at hospitals.
Orlando Mayor Buddy Dyer says at first officers mistakenly thought the gunman had strapped explosives to the dead victims and that the club was boob-trapped. A bomb robot sent back images of a battery part next to a body.
Dyer says that held up paramedics from going in until it was determined it was something that fell out of an exit sign or a smoke detector.
The robot was sent in after SWAT team members put explosive charges on a wall and an armored vehicle knocked the wall down in an effort to rescue hostages.
3:35 p.m. UPDATE:
A law enforcement official says the gunman who killed 50 people at a gay nightclub made a 911 call from the club, professing allegiance to the leader of the Islamic State, Abu Bakr al-Baghdadi.
The law enforcement official is familiar with the investigation but was not authorized to discuss the matter publicly and spoke on condition of anonymity.
Authorities say Omar Mateen opened fire at the Pulse nightclub in Orlando, killing 50 people and wounding more than 50 others before he was gunned down by police.
It was the deadliest mass shooting in modern U.S. history. Authorities were investigating the attack on the Florida dance club as an act of terrorism.
3:20 p.m. UPDATE
A former Afghan official says the father of the Orlando nightclub gunman is a native of Afghanistan who appears on a television program known for "its anti-US tirades" and "pro-Taliban" remarks.
The official says the gunman's father is Seddique Mateen and that the program is broadcast in the Dari language. The official spoke only on condition of anonymity because he did not want to be linked to coverage of the shooting.
Mateen is the father of Omar Mateen, who authorities say killed 50 people at the nightclub.
The official said Seddique Mateen's "Durand Jirga Show" is anti-Pakistan. The name of the show references the Durand line, the long disputed border between Afghanistan and Pakistan.
Seddique Mateen campaigned in the United States for current Afghan President Ashraf Ghani, who appeared on his program in 2014. The program's studio has an address in Fort Pierce, Florida.
Afghanistan's president says he "strongly condemns" the attack on a Florida nightclub that killed at least 50 people.
President Ashraf Ghani said in a statement Sunday that "targeting civilians is not justifiable under any circumstances whatsoever." He offered his condolences to President Barack Obama, the American people and the families of the victims.
Afghanistan Chief Executive Abdullah Abdullah also offered his condolences.
Shooter Omar Mateen was born in New York. His ex-wife told The Washington Post that Mateen's family was from Afghanistan. The family later moved to Florida.
The ex-wife is not named in the Post report.
3:05 p.m. UPDATE:
The FBI says agents twice investigated the man who killed 50 people inside a gay nightclub, but closed those cases after interviewing him.
FBI agent Ronald Hopper said Sunday that Omar Mateen had been interviewed in 2013 and 2014. Hopper said agents first investigated Mateen after he made inflammatory comments to co-workers alleging possible ties to terrorists.
Mateen was interviewed twice and, when investigators were unable to verify the details of his comments, the FBI closed the probe.
In 2014, the agency looked into potential ties connecting Mateen to Moner Mohammad Abusalha, the first American to carry out a suicide attack in Syria. Like Maten, Abusalha lived in Fort Pierce, Fla.
Hopper says agents determined that contact was minimal and did not constitute a substantive relationship or a threat at that time.
Mateen was 29 years old and born in New York. The FBI says he referred to the Islamic State in a 911 call before the slayings.
2:45 p.m. UPDATE:
The city of Orlando is publishing the names of those killed in a massacre at a gay nightclub on its website after their families have been contacted.
As of 2:45 p.m. Sunday, the list had four names. Fifty people were killed.
Shooter Omar Mateen was killed; his name is not on the list.
Fifty-three more were hospitalized.
The city's website includes the #PrayforOrlando hashtag and says officials are "working tirelessly" to get information to families.
The list can be found at http://www.cityoforlando.net/blog/victims/
2:25 p.m. UPDATE:
The ex-wife of the man authorities say killed 50 people at an Orlando nightclub says he beat her repeatedly while they were married.
The ex-wife told The Washington Post that she met Omar Mateen online about eight years ago and decided to move to Florida and marry him. The ex-wife, who wasn't named in the report, says at first the marriage was normal, but then he became abusive.
They were together for only a few months and her parents intervened when they learned Mateen had assaulted her. She says he wasn't very religious and gave no signs of radical Islam. She said he owned a small-caliber handgun and worked as a guard at a nearby facility for juvenile delinquents.
Mateen's ex-wife said his family was from Afghanistan, but her ex-husband was born in New York. His family later moved to Florida.
2:20 p.m. UPDATE:
Officials are giving more details about the shooter in a massacre at a gay Orlando nightclub.
Ronald Hopper of the FBI says shooter Omar Mateen was 29 and an American citizen. He was not under surveillance at the time of the shooting.
Hooper says Mateen purchased at least two firearms legally within the last week or so.
Hooper says some 911 calls involving the shooter and the massacre have become federal evidence. He says the conversations involved the Islamic State.
Hooper says the shooter in 2013 made inflammatory comments to co-workers, and that Mateen was interviewed twice. Hooper calls those interviews inconclusive.
In 2014, Hooper says, officials found that Mateen had ties to an American suicide bomber. Hooper describes the contact as minimal; it did not constitute a threat at that time.
3:15 p.m. UPDATE:
Police say 11 officers exchanged gunfire with the shooter at a Florida nightclub.
Orlando police Chief John Mina gave the details at a Sunday afternoon news conference.
Also, officials say three deputy sheriffs actively engaged, and fired their weapons. They're relieved of duties pending an investigation. That's typical procedure in such cases.
3:15 p.m. UPDATE:
The suspected Orlando night club shooter Omar Mateen was a security guard with G4S. In a 2012 newsletter, the firm identified him as working in West Palm Beach.
In a statement sent to the Palm Beach Post, the security company confirmed his employment.
"We are shocked and saddened by the tragic event that occurred at the Orlando nightclub. We can confirm that Omar Mateen had been employed with G4S since September 10, 2007. We are cooperating fully with all law enforcement authorities, including the FBI, as they conduct their investigation. Our thoughts and prayers are with all of the friends, families and people affected by this unspeakable tragedy."
2 p.m. UPDATE:
Multiple news outlets are reporting that the man who killed 50 people at a gay nightclub in Orlando called 911 shortly before the attack and pledged allegiance to the Islamic State.
The media outlets cited unnamed law enforcement officials in their reports.
Danny Banks is an agent with the Florida Department of Law Enforcement. He says authorities are investigating whether the deadliest mass shooting in modern American history was an act of domestic or international terrorism, and if the shooter acted alone.
The suspect in the Orlando attack was identified as Omar Mateen of Port St. Lucie, Florida. The gunman's father recalled to NBC News that his son recently got angry when he saw two men kissing in Miami and said that might be related to the assault.
1:55 p.m. UPDATE:
People who were inside the gay Florida nightclub where 50 people were killed are describing a scene of mass chaos.
Two men who were in Club Pulse discussed the Sunday massacre in Facebook chats with The Associated Press.
Orlando resident Brand White was shot. He says, "We are dancing and all of a sudden it just started like a rolling thunder, loud and everything went black."
The 30-year-old was with his cousin, who mentioned something about "a guy with a bomb." After that, White says, his memory is fuzzy; he said he doesn't recall leaving the club or who took him to the hospital.
White was shot in the shoulder. He spoke to The AP as he was being monitored at a hospital. He said he received a blood transfusion.
His cousin was unaccounted for — no one had heard from him as of 2:45 p.m.
Another man, Brett Rigas, says he and his partner were dancing when they heard shots. Rigas was shot in the arm and hid behind a bar. About five minutes later, authorities came in and told everyone to put their hands up and run out.
Rigas said he saw bodies as he ran out.
1:45 p.m. UPDATE:
The suspected Orlando nightclub gunman had been licensed as a private security officer in Florida.
State records show suspected shooter Omar Mateen held the firearms license since at least 2011. It was set to expire in September 2017.
It wasn't immediately clear where, if anywhere, Mateen had worked as a security officer. An armed guard license in Florida requires 28 hours of classroom training by a licensed instructor.
1:25 p.m. UPDATE:
Police departments across the country are increasing patrols near locations frequented by the LGBT community after a gunman killed 50 people at a gay nightclub in Orlando.
In Los Angeles, the mayor says a heavily armed person who was headed to a gay pride parade had been arrested by Santa Monica police. Mayor Eric Garcetti says the arrest was completely unrelated to the Orlando nightclub shooting.
Officer Ernesto Rodriguez of Miami Beach Police Department says the agency is saddened by the massacre and out of an abundance of caution will step up patrols. Boston Pride organizers plan to hold a moment of silence at this weekend's scheduled block parties to honor the Orlando victims and police there said there will be a heavier presence at those events.
The Baltimore Police Department says it is reaching out to the city's LBGT community to discuss concerns and safety after the Orlando massacre.
1:05 p.m. UPDATE:
President Barack Obama says the nightclub shooting in Orlando was an "act of terror" and an "act of hate."
He said Sunday that the FBI is investigating it as an act of terrorism and that no effort will be spared to determine whether the shooter was affiliated with terrorist groups.
Obama is speaking at the White House after 50 people were killed overnight at a nightclub in Florida. Officials have said 53 more are hospitalized.
Obama is noting that the killer targeted a gay nightclub. He says it's a "sobering reminder" that an attack on any American is an attack "on all of us."
12:35 P.M. UPDATE:
A law enforcement official says the shooter in the massacre at a gay Florida nightclub was known to the FBI and had been looked at by agents within the last few years.
The official spoke to The Associated Press Sunday about the shooting, the deadliest in U.S. history. The official was not authorized to discuss the ongoing investigation and spoke on condition of anonymity.
The shooter has been identified as Omar Mateen of Florida. The official says the matter for which Mateen came under investigation was "open and closed pretty quickly."
Other details about the matter weren't immediately available.
12:20 P.M. UPDATE:
Hundreds of people in Orlando have lined up to give blood to help the victims of the massacre at a gay nightclub.
Officials at OneBlood say they have received such an overwhelming response that they are now asking donors to come back over the next several days. More than 50 people were injured and 50 were killed when a gunman opened fire inside a gay nightclub in Orlando early Sunday morning.
In the hours after the worst mass shooting in U.S. history, officials urged people to donate blood to help the victims.
In December, the nation's three-decade-old ban on blood donations from gay and bisexual men was formally lifted, but there are still major restrictions to limit who can give blood. The Food and Drug Administration said it replaced the lifetime ban with a new policy barring donations from men who have had sex with a man in the previous year.
11:45 A.M. UPDATE:
The ranking Democrat on the House Intelligence Committee says law enforcement officials and the intelligence community are checking to see what information they had on the shooter before the massacre at a gay Florida nightclub.
Rep. Adam Schiff called the attack "painfully reminiscent" of the November shootings at the Bataclan Theatre in Paris.
He said in a statement: "This morning, I will be marching in the West Hollywood Pride Parade with a heavy heart, but we will march in solidarity with all those who are the victims of terrorism and hatred."
Check back with Arkansas Online for updates on this developing story and read Monday's Arkansas Democrat-Gazette for full details.
11:30 A.M. UPDATE:
Florida Gov. Rick Scott is calling the shooting at a gay Orlando nightclub "heart-wrenching" and says people who went into the building knowing there was an active shooter are heroic.
He spoke Sunday afternoon at a news conference, hours after 50 people were killed. Officials have said 53 more are hospitalized.
Scott urged people to donate blood. He said officials are doing everything they can.
He said the massacre was "clearly an act of terror."
He adds, "To take that number of lives is clearly an act of terror."
Officials have said they're investigating whether the incident was an act of terrorism.
11 A.M. UPDATE:
A SWAT truck and a bomb disposal unit are on the scene of an address associated with the man named as the shooter in a massacre at a gay nightclub in Orlando.
There is a media staging area set up about a block away from the apartment complex in a residential neighborhood in Fort Pierce, Fla., on Sunday. The shooter has been identified Omar Mateen.
Fort Pierce is about 118 miles southeast of Orlando. The apartment complex is a series of two-story buildings.
Numerous police officers and members of the FBI also are there.
10:20 A.M. UPDATE:
Families and friends are awaiting word outside an Orlando hospital to learn whether their loved ones are among 50 killed and 53 more hospitalized at a shooting at a gay nightclub.
About 50 people were gathered outside Orlando Regional Medical Center on Sunday, many in tears and anxious.
Fatriana Evans frequents the Pulse nightclub and was outside when shots were fired.
Evans says, "It sounded like fireworks — pop, pop, pop — and then everybody scatters."
Jackie Smith was inside the club and said two friends next to her were shot. She said she hasn't gotten updates on their conditions. She came out of the hospital and burst into tears in the arms of friends.
She said: "Some guy walked in and started shooting everybody. He had an automatic rifle, so nobody stood a chance. I just tried to get out of there."
10 A.M. UPDATE:
Police say the shooter at an Orlando nightclub used an AR-15-type assault rifle on all the victims.
Officials say 50 were killed at the popular gay club. That makes it the deadliest mass shooting in U.S. history.
Police Chief John Mina said at a Sunday news conference that the shooter used the assault rifle, with unknown rounds, and also had a handgun.
Officials at the news conference also said they have secured the suspect's vehicle, a van, right outside the club.
The shooter has been identified as Omar Mateen of Port St. Lucie, Fla. Officials have said they're investigating whether the massacre was an act of terrorism.
Dr. Mike Cheatham is a trauma surgeon at Orlando Regional Medical Center, where 46 patients were taken. The majority are in critical condition.
He told The Associated Press, "I think we will see the death toll rise."
9:50 A.M. UPDATE:
The massacre at an Orlando nightclub that claimed 50 lives is the worst mass shooting in U.S. history.
Police Chief John Mina confirmed at a news conference Sunday morning that 50 people were killed, up from 20 as earlier reported.
Mayor Buddy Dyer said 53 more are hospitalized after the early Sunday incident. He said the shooter is among the dead. He also said the shooter used an assault rifle on all those dead. Officials said one officer was shot and has injuries to his face.
EARLIER:
The mayor of Orlando says there were 50 casualties and there are 53 more hospitalized after a mass shooting at a popular gay nightclub there.
"There's blood everywhere," Mayor Buddy Dyer said Sunday at a news conference, hours after the shooting.
He says the shooter used an assault rifle on all those killed.
The suspect has been identified as Omar Mateen of Port St. Lucie, Fla.
U.S. Rep. Alan Grayson identified the shooter in the Sunday massacre. He cited law enforcement officials in speaking to reporters.
A federal law enforcement official with knowledge of the investigation also identified him. The official was not authorized to discuss the investigation publicly and spoke on condition of anonymity.
Florida Department of Law Enforcement Special Agent in Charge Danny Banks said earlier that the mass shooting is being investigated as an act of terrorism. He said authorities are looking into whether the shooter was an act of domestic or international terror and if the shooter was a lone wolf.
Police chief John Mina said the shooter was armed with an assault-type rifle, a handgun and some type of suspicious device. Police had said previously on Twitter that there was a "controlled explosion" at the scene of the shooting at Pulse Orlando, a popular gay dance club. Mina says that noise was caused by a device intended to distract the shooter.
Mina also said the suspect had exchanged gunshots with an officer working at the club, then went back inside and took hostages around 2 a.m. About three hours later, a SWAT team made the decision to go inside and rescue the hostages. The shooter died in a gunfight with those officers.
Dozens of emergency vehicles have swarmed the area around the club.
The club, Pulse Orlando, earlier posted on its own Facebook page just after 2 a.m.: "Everyone get out of pulse and keep running."
The shooting follows the fatal shooting on Friday of 22-year-old singer Christina Grimmie, who was killed after her concert in Orlando by a 27-year-old Florida man who later killed himself. Grimmie was a YouTube sensation and former contestant on The Voice.