Vietnam Helicopter Crash
Airforce personnel guard the area outside the site of a military helicopter crash, outside Hanoi. Reuters

A Russian-made MI-171 military helicopter has crashed near the Vietnamese capital Hanoi, killing 19 people and injuring two others, according to officials.

Lieutenant General Vo Van Tuan, deputy chief of the general staff, revealed that the helicopter had crashed because of a technical failure.

"The plane was carrying 21 people and it crashed during a parachute training exercise, killing 16 and injuring five others," he said initially, before the death toll was updated.

"Our priority now is to look after the five injured, some who are in serious condition."

All of those killed and injured in the crash were military personnel, confirmed Tuan.

An eyewitness said that the helicopter flew at a low level before crashing into the ground and catching fire.

"The aircraft was flying low, it hit the ground and exploded at the same time," a local resident told AFP.

"It seemed like the pilot wanted to divert the plane from hitting the local market and houses, so it ran into a field."

The majority of the Vietnamese military's fleet has been purchased from Russia and is reported to be ageing. In a 2008 accident, five military pilots were killed when their aircraft crashed just outside Hanoi.

The MI-171 model is a twin-engine transport helicopter and is also used by Chinese and Indian military forces.