Pro-Federalist separatists in eastern Ukraine confirmed to Russia’s RT network that they attacked a Ukrainian military helicopter with a rocket-propelled grenade (RPG) on Friday.

There are conflicting reports on casualties, with some saying up to three people were killed, while others claim there were no casualties. The most agreed-upon story is that the grenade round hit the fuel tank while it was being loaded and the pilot managed to escape, but was injured.

"An army Mi-8 helicopter has exploded at the Kramatorsk aerodrome," said the Ministry of Defense in a statement.

Footage shows the helicopter on fire before violently exploding, sending shrapnel flying over a cameraman’s head.

The exact details of the explosion are still unclear. While the Ministry of Defense claims it was an RPG that blew up the helicopter, the security service of Ukraine says it was a sniper that fired a shot that hit the fuel tank, causing the explosion.

Kramatorsk is located in the northern part of the Donetsk Oblast, which declared independence from Ukraine earlier this month. The entire region is a hotbed for anti-Kiev militants.

Who exactly the aggressors are remains a mystery. The largely pro-Kremlin RT calls them “self-defense forces,” a blanket term often used by the Russian leadership to identify the ranks of mysterious armed men across Crimea and eastern Ukraine. They quote a “representative from the Kramatorsk self-defense troops” claiming responsibility.

“Our people approached the airfield, shot a rocket-propelled grenade in the direction of the helicopter,” said the representative, “There was an explosion. [Kiev] militants started shooting and we [protesters] retreated.”

Russian President Vladimir Putin admitted last week that the armed men in Crimea were at least partly Russian troops, after a month of denying so, saying they too were ‘self-defense forces.’ Many suspect the same is happening in eastern Ukraine.

Evidence shows that at least one Russian commander made his way into eastern Ukraine to take command of police forces:

A separatist commander confirmed in a taped interview that he and his men came from Crimea at the request of eastern Ukrainian separatists. Kiev calls him a Russian intelligence officer.

"The unit that I came to Sloviansk with was put together in Crimea. I'm not going to hide that," Mr. Strelkov said, "It was formed by volunteers—I would say half or two-thirds of them citizens of Ukraine."

He also spoke about the helicopter attack, saying that militants had the opportunity to attack helicopters carrying men, but instead went for the one that was only carrying weapons and ammunition. He says that is because the separatists to do not want to hurt their fellow Ukrainians, even though they're ideologically opposed to them. That sentiment has been echoed by Ukrainians on both sides, and illustrates how deeply personal the conflict is for many Ukrainians.