NOVOHANNIVKA, Ukraine -- Pro-Russia separatists shot down a Ukrainian military transport plane Saturday, killing all 49 crew members and troops aboard.
It was the deadliest event yet in the Ukrainian forces' battle against an armed insurgency that the government, backed by the U.S., says is supported by Russia. It also came only a week after the new president, billionaire candy magnate Petro Poroshenko, spoke about a peace plan in his inaugural address.
Poroshenko called an emergency meeting of Ukraine's national security council and declared today a day of national mourning.
"All linked to this terrorist action of such scale will be punished, for sure," Poroshenko said on his website.
Afterward, the president scolded the head of the country's security service, referring to "omissions" in measures to protect military aircraft from attack. He called for "a detailed analysis of the reasons" and hinted that personnel changes were imminent.
The U.S. government reiterated its support for Poroshenko's government and rejected Russia's statements that it was not arming the rebels.
Secretary of State John Kerry also called Ukraine's prime minister, Arseniy Yatsenyuk, and assured him that the U.S. and its European allies were prepared "to raise the costs for Russia if it does not end the flow of weapons across the border and break with separatists," a State Department official said, a reference to the additional sanctions President Barack Obama has said would be imposed on Russia if it continues its support to the Ukrainian separatists.
The U.S. said Friday that Russia had sent tanks and rocket launchers to the rebels, making sure the unmarked tanks were of a type currently not being used by Russian forces.
A convoy of three T-64 tanks, several BM-21 multiple rocket launchers and other military vehicles crossed the border near the Ukrainian town of Snizhne, the State Department official said. The Ukrainian army reported Friday that it had destroyed two of the tanks and several other vehicles in the convoy.
"We condemn the shooting down of the Ukrainian military plane and continue to be deeply concerned about the situation in eastern Ukraine, including by the fact that militant and separatist groups have received heavy weapons from Russia, including tanks, which is a significant escalation," said White House spokesman Laura Lucas Magnuson.
German Chancellor Angela Merkel and French President Francois Hollande called Russian President Vladimir Putin to express their "dismay" over the downing of the plane and said the attack makes clear how urgent a cease-fire is, German government spokesman Georg Streiter said in a statement.
Merkel stressed that for a cease-fire to last, Russia must effectively control its border with Ukraine to stem the flow of weapons and fighters.
Analysts said the downing of the plane could draw a renewed emphasis on increasing sanctions against Russia.
The attack "will refocus attention on the fact that Russia does not seem to be doing very much to moderate the insurgency [or] the cross-border resupply of separatists," said Timothy Ash, an analyst at Standard Bank PLC. "Comments from U.S. officials are now quite specific, and I would expect the focus to return to sanctions next week."
Nine crew members and 40 troops were aboard the Il-76 troop transport when it went down early Saturday as it approached the airport at Luhansk, the Ukrainian prosecutor general's office said. Defense Ministry spokesman Bohdan Senyk said the rebels used anti-aircraft guns and a heavy machine gun to down the plane, while the prosecutor general's office said rebels used an anti-aircraft missile.
A surveillance video that captured the plane's destruction showed a streak of light rising from the ground, then an explosion near the airport where the plane was making its final approach to Luhansk.
Luhansk, a city near the border with Russia, is one of two eastern areas where separatists have seized government buildings and declared independence. Ukrainian forces still control the airport there.
The plane crashed into a barley field about 12 miles from the airport. Parts of the four-engine jet plane were mangled beyond recognition, and all were scattered about.
The plane had been packed with ammunition, and as it fell or when it hit, some exploded, leaving empty shells among the rubble, along with intact rounds and unexploded grenades.
By late afternoon, scavengers from a nearby village were walking gingerly through the site.
"Brother kills brother. When will this end?" said one man, who offered only his first name, Taras. "I heard the plane when it exploded last night. How many mothers won't see their sons again? And for what?"
The death toll Saturday exceeded the 46 who died after a fire and shootings in Odessa on May 2. At least 40 people also died in fighting at Donetsk airport in late May, and a rebel spokesman said the toll on his side that day may have been as high as 100.
The Kiev government has accused Russia of permitting three tanks to cross the border last week into eastern Ukraine, where they were used by rebels. Russia denies supplying the separatists and says Russians fighting in Ukraine are volunteers.
Moscow did not respond to the tank reports and accused the Ukrainian military of violating the border several times, including Friday when a Ukrainian armored vehicle ventured about 490 feet into Russia. The Russian Foreign Ministry warned Saturday that if the incursions continued it would "take all necessary measures to suppress them."
NATO, meanwhile, released images Saturday that it said showed recent Russian tank movements near the border. It said the tanks seen in eastern Ukraine "do not bear markings or camouflage paint like those used by the Ukrainian military." It said those tactics were used by the Russians who seized Crimea in March.
Tensions between Ukraine and Russia escalated in February after pro-Russia President Viktor Yanukovych was driven from office by protesters who wanted closer ties with the European Union and an end to the country's endemic corruption. Russia then seized and annexed Ukraine's Black Sea peninsula of Crimea.
The U.S. and Europe rejected the annexation and responded with financial sanctions targeting individuals. They have threatened to further extend the sanctions to the Russian economy.
The EU, meanwhile, reported that senior officials from Ukraine and Russia, including Yatsenyuk and Gazprom Chief Executive Officer Alexei Miller, were holding talks late Saturday in Kiev about their natural gas dispute.
Russia says Ukraine owes billions in unpaid gas debts and has set a deadline of Monday before it will demand upfront payments for gas supplies. Ukraine disputes the debt amount and, with its economy in dire straits after the departure of Yanukovych, has little ability to repay.
Gazprom rescinded a price discount granted to Ukraine in December, citing the country's mounting debt, while Russia stripped its neighbor of a 2010 export duty break that it exchanged for a lease on its Black Sea fleet's port in Crimea, a region Putin annexed in March.
Also in Kiev, about 100 protesters hurled eggs Saturday at the Russian Embassy and overturned several parked cars with diplomatic plates, holding a sign saying "Russia is a killer."
Meanwhile, five border guards were killed and seven wounded Saturday when rebels attacked a convoy near the eastern coastal town of Mariupol, the State Border Service said on its website.
Information for this article was contributed by David McHugh, Marko Dobrnjakovic and Lynn Berry of The Associated Press; by Andrew E. Kramer and Michael R. Gordon of The New York Times; and by Daryna Krasnolutska and Volodymyr Verbyany of Bloomberg News.
A Section on 06/15/2014