The Ukrainian Ministry of Defense released a statement regarding the attack:
"Two Mi-24 helicopters of the Armed Forces of Ukraine were shot down over Sloviansk in Donetsk region early on May 2 while on a patrol mission. According to preliminary reports, the combat aircraft were shot down by unknown individuals using man-portable air defense systems (MANPADS). As a result of the shooting, two servicemen were killed and several others sustained injuries."
As a State Emergencies Service helicopter arrived on the scene to attend to the wounded, the team of doctors came under fire and one doctor was wounded.
Another pilot was abducted by the assailants but, according to the defense minister's adviser, Yuiry Povkh, "the location of the officer has now been established, and as far as we are informed, he is undergoing surgery in a medical institution."
The use of MANPADS, the ministry said, demonstrates that the group was well-trained and intent on destabilizing the region, contradicting claims that unrest has been caused by "peaceful protesters."
"This behavior is characteristic of the military of another country, who act against an 'enemy' determined by their leadership, or mercenaries with considerable experience who are ready to act against anyone for cash or another reward."
Four suspects in Friday's helicopter attack have been detained, the defense minister's adviser said. They were stopped later in the day at a checkpoint near Sloviansk "as part of the anti-terrorist operation."
Notable deaths of 2014 [PHOTOS]