CLEAN : Rebels down Ukraine military plane killing 49

Ukrainian police disabled an aircraft's engine with gunfire at a checkpoint. The aircraft crashed before reaching the airport. Heavy military equipment, including combat vehicles and large-caliber machine guns, was found at the site. The troops were identified as the 25th Airborne Brigade. Evidence suggests they were searching for the black box and retrieving bodies.

What evidence suggested the presence of airborne troops?

What was the likely purpose of the search conducted by the troops?