The Soviet-era MI-171 helicopter was on a training flight when it went down early yesterday morning, said Lieutenant general Vo Van Tuan, deputy chief of staff of the army.
He said: "The reason for the crash was technical problems. This is a serious loss for us."
Mr Tuan added the only casualties were among those aboard the helicopter, with no civilians hurt.
Fire engines were seen arriving at the scene and people carried away what appeared to be pieces of wreckage.
Troops and police blocked journalists from entering the crash site, which is close to a military airport and a housing area about 20 miles west of the city centre.
Those on board were thought to be paratroopers.