The bomb was found in an MTR construction site in Wan Chai on Hong Kong Island. Photo: HK Police

Police defused a World War II bomb found at an MTR construction site in Wan Chai on Hong Kong Island around noon on Friday, almost 20 hours after they started working on it.

The 1,000-pound bomb, believed to have been dropped from an American plane during the Japanese occupation of Hong Kong between 1941 and 1945, was found Thursday at an MTR construction site for the Shatin-Central rail link, the Oriental Daily reported.

It was in the same location where two similar bombs were unearthed within days of each other in January.

On Friday morning, police bomb disposal experts cut a hole in the bomb and burned off the explosives to make the device safe.

Bomb disposal officer Nestor Lai said the operation to defuse the explosive was quicker than previous ones due to the experience officers had gained thanks to the previous discoveries in January, Radio Television Hong Kong reported.

But Lai said the challenge this time was that much of the bomb was still buried. After finished defusing it, major roads and flyovers in north Wan Chai which had been cordoned off since Thursday evening were reopened.

Read: Police take 26 hours to defuse WWII bomb found in Wan Chai

Read: Police defuse second big WWII bomb found in Wanchai