Pro-Ukrainian people overturn a car during a rally in front of the Russian embassy in Kiev June 14, 2014. The rally was held to demand Russian authorities and President Vladimir Putin to stop supporting groups of separatists in eastern Ukraine, according to the protesters. REUTERS/Valentyn Ogirenko

UPDATE (3:55 EDT): Kateryna Kruk, a Ukrainian activist who was at the protest told IBTimes that activists originally planned for the protest to only be a picket "to show our anger and point out Russian hand in the East," but it turned more violent when members of the Maidan "self-defense unit" arrived. She says members of the far right Svoboda party took the Russian flag down.

Photos show protesters flying the distinctive red and black flag of the Ukrainian Insurgent Army (UPA) outside the embassy. The UPA was a partisan army that fought against Nazi Germany and the Soviet Union during the 1940s.

She says she left soon after protesters began throwing cobblestones and flipping cars because she no longer agreed with the protest.

UPDATE (2:24 EDT): U.S. State Department condemns the attack on the Russian Embassy.

Ukrainian protesters vandalized the Russian Embassy in Kiev on Saturday in a dramatic display of anger over Russia's alleged support of eastern separatists.

Pro-Ukrainian activists snapped photos of the protest that show the overturned cars of Russian diplomats and protesters taking down the Russian flag from the embassy building. Protesters threw eggs at the embassy building and drew swastikas on diplomats' cars. Separate unconfirmed reports say protesters hung the Ukrainian and/or Right Sector flag from the embassy.

The protest come after eastern separatists shot down a Ukrainian military plane with heavy machine guns and anti aircraft missles in the eastern city of Luhansk, killing all 49 people on board. Newly elected President Petro Poroshenko vowed an "adequate" response.

"All those involved in cynical acts of terrorism of this magnitude must be punished," Poroshenko said.

NATO also released a statement on Saturday that all but accuses Russia of providing tanks and other heavy weaponry to eastern separatists earlier this week. Three T-64 main battle tanks and a slew of other heavy military equipment were spotted by Ukrainian military patrosl and journalists moving through the city of Snizhne, in the eastern province of Donetsk on Thursday. The U.S. State Department said it was "confident" the tanks came from Russia.

A live stream of the Russian Embassy rally in Kiev can be viewed below.

Broadcast live streaming video on Ustream