June 15 was a day of mourning in Ukraine for 49 soldiers killed when pro-Russian separatists shot down a military transport plane.
Ukrainian President Petro Poroshenko declared the day of mourning and has vowed a firm response against those who shot down the aircraft early on June 14 as it approached the airport in Luhansk.
"Ukraine is in sorrow, but we strongly continue the struggle for peace," Poroshenko said.
Shortly after Poronshenko's speech on June 14, a crowd of several hundred people in Kyiv smashed windows in the Russian embassy and overturned luxury cars belonging to Russian embassy staff before pulling down the Russian flag.
Russia's Foreign Ministry on June 15 sent a protest note to Kyiv demanding that those responsible for the attack be caught and punished.
Russia condemned the failure of Kyiv's police to stop the angry crowd, calling it "a grave violation of Ukraine's international obligations."
A Molotov cocktail also was thrown against a wall of the Russian embassy but the fire was quickly extinguished.
A sign carried by protesters in the crowd declared "Russia is a killer."
One Ukrainian woman in the crowd, who gave her name as Tetyana, said she thinks there would not be a crisis in eastern Ukraine without Russian support for the separatists there.
In Washington, the White House condemned the shooting down of the plane, saying that it is a "fact" that pro-Russian separatists in eastern Ukraine have received heavy weapons from Russia, including tanks and rocket launchers.
Meanwhile, NATO has released satellite imagery that gives added weight to claims by Kyiv that the separatists in eastern Ukraine are using tanks supplied by Russia in recent days.
The imagery shows three Russian T-64 tanks loaded onto transporters in a military convoy close to the Ukrainian border on June 11 in the Russian region of Rostov.
NATO officials say they have no doubt it is the same military convoy that crossed the border into Ukraine later on June 11.
A senior NATO official has told the BBC that the satellite images "raise significant questions concerning Russia's role in facilitating instability in eastern Ukraine.
Russia denies supplying tanks and weaponry to separatists in Ukraine.
Denis Pushilin, a pro-Russia separatist leader in Donetsk, told Russian state television on June 13 that rebels in Donetsk had obtained tanks. But he said it was "improper to ask" where they had gotten them.
With reporting by Reuters, AP, BBC, and ITAR-TASS