A Vietnamese military helicopter on a parachute training mission crashed close to the Vietnamese capital on Monday, killing 16 people on board and critically injuring five others, officials and state-controlled media said.
The Russian-made MI-171 helicopter came down about 15 minutes after takeoff in a small village about 24 miles (40 kilometers) west of Hanoi.
A doctor at a military hospital said 16 people were killed and five others were being treated for serious burn injuries.
The injured were being treated in the national burns hospital in Hanoi. A doctor there said they had only a slim chance of survival. The doctors didn't give their names because they weren't authorized to speak to the media.
Reports in the state-controlled media said 16 of those on board were parachute recruits from the air force's helicopter regiment. There were also two trainers and three crew members on board.
Lt. Gen. Vo Van Tuan, Vietnam military deputy chief of staff, was quoted as saying technical problems, not sabotage of any kind, were suspected in the crash. He said the pilot of the chopper successfully steered it away from a residential area, preventing loss of life on the ground.
The MI-171 helicopter is primarily a transport aircraft, but there is also a gunship version.
Vietnam buys most of its military hardware from Russia, the country's cold war ally. Some of it dates back more than 20 years.