HONG KONG (AFP) -- Dozens of people were evacuated Monday after a World War II bomb was discovered at a construction site in Hong Kong, near a university campus and staff quarters.

67 residents at three blocks of a university hall were moved after the 500-pound (227 kilograms) US-made aerial bomb was unearthed on Pok Fu Lam Road, police confirmed.

The bomb was to be detonated on site Monday evening and treated with an "abrasive water-cutting system", a bomb disposal expert told reporters. The whole process was estimated to take around three hours.

Pedestrians and vehicles would be barred from entering the premises, and residents in the blocked area were urged to stay indoors and away from windows in case of accidents.

Unexploded wartime bombs or grenades are frequently found by hikers or construction workers in the southern Chinese city, which was the scene of fierce fighting between Japanese and British allied forces in 1941.

US and allied air forces bombed Japanese occupiers after the then-British colony fell.

Last year police disposed of eight explosive devices found by a hiker.

In 2014 police defused a wartime bomb weighing nearly one ton, the largest yet found in the city. More than 2,200 people were evacuated.