Soldiers are handling two big unexploded bombs that have recently been discovered in Hanoi, Tien Phong quoted the High Command of the capital as saying on Thursday.

According to the newspaper, one of the bombs was unearthed Tuesday when workers were upgrading the Dinh Ngoc Ha Lake in Ba Dinh District.

The bomb was probably from a Boeing B-52 Stratofortress that Vietnamese soldiers shot down during a battle against the US’s Operation Linebacker II – a massive bomber strike in Hanoi at the end of December 1972, local agencies said

The other bomb was detected on Wednesday in Trung Van Commune, Tu Liem District, Tien Phong reported.

Official figures showed that about 6.6 million hectares (16.3 million acres) of land, more than 20 percent of the country’s total surface area, has been affected by unexploded ordnances (UXOs) left behind by the Vietnam War.

Experts have estimated that it would take hundreds of years and billions of dollars to clear Vietnam of leftover bombs, shells and mines.