On Tuesday, Ukrainian military officials said they suspected Russia of carrying out an airstrike that destroyed a four-story apartment building in the eastern Ukrainian town of Snizhne, about 12 miles from border, killing at least 11 civilians.
Pro-Russian separatists, in turn, said the Ukrainian military had carried out the bombing.
The announcement by Ukraine’s general prosecutor’s office that it was collecting evidence of a Russian role in the airstrike came a day after the government in Kiev said it believed Russia was responsible for the downing of a military transport plane in Luhansk.
A day before that, the Russian Foreign Ministry warned of potentially “irreversible consequences” after one man was killed and two other people were wounded when mortar fire hit the town of Donetsk on the Russian side of the border.
Officially, the Kremlin has denied arming, financing or directing the insurrection in eastern Ukraine, but its active support of the rebellion has been openly acknowledged in recent days.
Separatist leaders have complained about the low quality and advanced age of the weapons provided by Russia and a lack of more proactive assistance as they have come under heavier attack by the Ukrainian military.
On Tuesday, apparent new evidence of Russian military aid appeared on the roads of eastern Ukraine as convoys of tanks and smaller vehicles drove west through rebel-controlled territory toward Donetsk.
Shortly after 10 a.m., a column of eight tanks, four large armored personnel carriers, and an assortment of smaller civilian cars and minivans wound its way through the small town of Vuglegirsk.
Rebels reclined on the top of the tanks, as if on couches.
A kiosk owner watched as they passed. “I’m just sick of it all,” said the owner, who would give only her first name, Larisa, out of concern for her safety.
She saved her harshest words for Ukraine’s government. “They are killing their own people,” she said.
“We won’t forgive them that.”
A half-hour later, a column of four tanks rolled down the same road, past a brilliant field of sunflowers.
Behind were trucks and civilian cars, including a new-looking Volkswagen minivan, with a blue light on top.
The continued supply of arms and equipment has riled officials in Kiev, including President Petro O. Poroshenko, who has urged the West to impose more painful economic sanctions against Russia.
Anatoliy Matios, a deputy general prosecutor, said at a news conference in Kiev that the Ukrainian government intended to show evidence of Russia’s involvement in the bombing of the residential building in Snizhne.“It will be proven according to international standards that a neighboring state used military equipment and ammunition,” Mr. Matios said.
While separatists blamed the government for the airstrike, Ukrainian officials insisted that all military flights had been suspended on Monday after the downing of the military transport plane in a rocket attack.
Russia on Tuesday denied that the rocket that destroyed the plane had been fired from its side of the border.
As the cross-border recriminations added new animosity to the fight, the death toll continued to mount from the separatist insurrection in eastern Ukraine and the Ukrainian military’s effort to quash the rebellion.
At least six more Ukrainian soldiers were killed and 13 wounded in overnight fighting throughout the east, Andriy Lysenko, a spokesman for Ukraine’s National Security and Defense Council, said at a news briefing on Tuesday.
The self-declared separatist Luhansk People’s Republic said that 15 civilians had been killed and more than 60 wounded in bombardments and other fighting throughout the region.
That did not include the 11 civilians killed in the airstrike in Snizhne.
Mr. Lysenko called the attack in Snizhne “a cynical and bloody provocation in order to discredit the Ukrainian military.”
Ukrainian officials have said that the downed cargo plane was flying at a high-enough altitude that destroying it required a sophisticated surface-to-air missile provided by Russia.
They also said it appeared that the missile had been fired from the Russian side of the border.
Russia denied that accusation on Tuesday, saying that the plane was shot down too far from the border to have involved a Russian missile.
A senior Western official, who declined to be identified because he was discussing intelligence reports, said that the information on the downing of the Ukrainian plane was inconclusive.
The official said that the initial conclusion of some government analysts was that the aircraft had probably been destroyed by a Russian surface-to-air missile and not a shoulder-fired antiaircraft system.
The official also said that the missile had probably been fired from the Russian side of the border, an assertion that was impossible to verify.
Western officials have generally been quick to support the Ukrainian version of events, and have repeatedly chastised the Kremlin for not doing enough to stop the flow of weapons and fighters across the border.
On Monday, the White House summoned European Union ambassadors to push for restrictions on the Russian financial sector and to show them intelligence documenting Russian support for separatists, Bloomberg News reported.
European Union leaders are scheduled to meet Wednesday to consider action.
If European allies do not go along, American officials said Mr. Obama might decide to go ahead with sanctions on his own, an approach he has tried to avoid for fear of allowing Russia to drive a wedge between the United States and Europe.
Source: The New York Times