The Russian Defense Ministry says four people were killed when a military helicopter crashed in the northwestern Pskov region on February 8.
The ministry said the Mi-8 helicopter went down during a routine training mission, killing "three pilots and a technical adviser."
The reason behind the crash was not immediately known. The ministry said a search-and-rescue team has arrived at the scene of the crash.
Accidents involving Mi-8 aircraft -- designed in the 1960s -- are frequent in Russia, which has been criticized for its poor air-safety record.
In June 2014, 15 people died when a helicopter crashed into a lake in the northern Murmansk region.