Two male suspects speaking with a northern Vietnamese accent used a gun and demanded staff of a BIDV branch in Dong Da District.

Hanoi police's initial investigations found that at around 9:55 a.m. Monday, two men with face masks and jackets walked from Nguyen Hong Street to the BIDV Ngoc Khanh branch at 27 Huynh Thuc Khang Street.

As soon as they stepped through the door, one of them took out what looked like a homemade gun and shot at the roof, shouting, "everybody sit still, put your hands in the air."

The man then went behind each of the counters and threw money over them to the other suspect who quickly put the cash into a backpack. The man who collected the money also threw a black bag on the floor saying it was full of explosives and threatening to trigger them if anyone tried to fight back.

The two then ran out of the bank and used the gun to intimidate a civilian who was withdrawing money from an ATM nearby. They took his plum-colored motorcycle with the license plate 29X2-137 and drove towards Thang Long Boulevard.

Police say the man holding the gun is between 1m65 and 1m68 tall. He wore brightly colored long trousers, a white cloth mask, a white baseball-cap helmet and dark shoes. The other, about 1m75 tall, has a slim body and wore dark trousers with sports shoes.

Hanoi-headquartered BIDV is one of Vietnam's largest banks by assets, with the state holding a majority stake.