BAGHDAD -- The Iraqi military will use a medieval tactic to keep control of Fallujah after recapturing it from the Islamic State militant group last month: It is digging a trench system around the city.
The trench system will have a single opening for residents to move in and out of the city, which is virtually empty since the offensive that defeated the Islamic State militants, said Lt. Gen. Abdul-Wahab al-Saadi, deputy commander of the counterterrorism forces that led the successful campaign.
The trenches will be about 7 miles long and "will protect the city's residents, who have lived through many tragedies, as well as security forces deployed there," al-Saadi said in an interview at his Baghdad headquarters.
Cutting off all roads but one will allow authorities to monitor the movements of residents more closely. Fallujah has been a source of car bombs used against Baghdad, which is 40 miles to the east. Restricting traffic will be one way to try to stop any explosives-laden vehicles from leaving the city.
Besides the trenches, more modern security measures also will be used.
Personal details of the estimated 85,000 residents who fled during the May-June battle to liberate the city will be stored electronically, and forgery-proof ID cards will be issued, according to Mayor Issa al-Issawi. Cars owned by residents will be issued display badges containing electronic chips.
The trenches will be about 40 feet wide and 5 feet deep.
Work has begun on the first leg, running about 4 miles on the north and northwest side of the city, al-Issawi said. Digging the second leg, which runs 3 miles along the south and southeast, will begin soon, he said.
The western edge of Fallujah abuts the Euphrates River, providing a natural barrier. On the east side is the heavily patrolled main highway to Baghdad, which will be the sole entrance to Fallujah.
The two trenches run through open desert areas used in the past by militants, said Maj. Gen. Saad Harbiyah, who is in charge of military operations in western Baghdad.
Iraqis have used various earthworks, walls and fortifications ever since the U.S.-led invasion that toppled Saddam Hussein in 2003. During the war, Hussein had trenches dug around Baghdad, filled them with oil and set them ablaze, using thick, black smoke to obscure the view from U.S. warplanes.
Since the war, Baghdad has become a city of concrete blast walls, erected to protect buildings but also to control the movement of people. During the 2006-07 sectarian violence between Shiites and Sunnis, entire neighborhoods were sealed off by blast walls to restrict and monitor access.
In January 2014, Fallujah became the first major Iraqi city to be captured by the Islamic State. The extremists later swept through much of Anbar province, taking its capital, Ramadi, and much of the north, including Iraq's second-largest city of Mosul.
A U.S.-led coalition and Iranian-backed Shiite militia forces have helped the Iraqi army recapture territory from the Islamic State.
The Iraqi government also plans to dig a trench along the border between Anbar province, where Fallujah is located, and neighboring Karbala, home to one of Shiite Islam's holiest shrines. Work also has begun on walls and trenches around vulnerable parts of Baghdad's outer areas to guard against car bombs. In both cases, however, work has been slowed by lack of funds and corruption.
Fallujah faces its own internal differences as well. Some factions of its main tribal clans declared allegiance to the Islamic State, while others did not, prompting the extremists to kill prominent tribal members and blow up the homes of those who fled.
Iraqi authorities arrested about 21,000 Fallujah residents from among those who fled the city on suspicion of Islamic State membership, al-Saadi said. After being questioned, all were released except for about 2,000 who face further interrogation and possible prosecution, he added.
Tens of thousands of displaced residents will be allowed to return to Fallujah later this year, al-Saadi said.
"We must turn a new page with Fallujah. There is no other way for reconciliation," said al-Saadi, a veteran of the government's fight against militants in Anbar.
"We must punish those with blood on their hands, but not those who merely joined Daesh," he said, using the Arabic acronym to refer to the Islamic State. "Revenge and mass trials will only breed more hatred and resentment."
Information for this article was contributed by Qassim Abdul-Zahra of The Associated Press.
A Section on 07/24/2016