A giant bomb left over from the Vietnam War has been found in the Red River in Hanoi below Long Bien Bridge.

Officials dispatched divers to inspect and identify the bomb on Sunday, although the object was first detected by local people in mid-November. The device is around 2.25 meters long (more than seven feet), 0.6 meters in diameter and is lying five meters from one of the bridge's pillars, they said.

“The bomb has been there for a very long time,” a local military official said. It remains unclear whether it has been detonated.

He said the city is awaiting instructions from the defense ministry and has banned boats from the area.

Decades after the Vietnam War ended, unexploded ordnance still threatens a fifth of the country’s land mass and explosions occur frequently, killing more than 1,500 people every year and maiming and injuring 2,200 more, according to official data.

The iconic Long Bien Bridge is 114 years old and was severely damaged by multiple American bombings between 1965 and 1972. It was the only way of crossing the Red River at the time.

The 2,290-meter bridge, which was renovated in 1973 and 2015, has a single-track railway in the middle with bike and pedestrian lanes on either side.