Three servicemen died in a helicopter crash in central Algeria, the defense ministry said Thursday, without specifying the cause of the crash.

The Russian-made MI-171 aircraft crashed on Wednesday night around 9:00 p.m. local time (2000 GMT) near the airport in the oasis town of El-Meniaa, the ministry said in a statement.

All three military personnel on board - a colonel, a lieutenant colonel and a sergeant - were killed, it added.

An investigation to determine the cause of the crash was opened at the request of armed forces chief General Said Chengriha, the statement added.