World War II preparation found in 2010

More than 900 unexploded bombs from World War II have been found beneath a restaurant in Okinawa, police said Thursday.

Construction workers on a road expansion project detected the explosives with a metal detector and notified police Wednesday morning, Kiyotaka Maedomari, a senior police official in Itoman city, said.

An army bomb disposal squad discovered the total of 902 unexploded bombs, believed to have been made in the United States, he said.

"It's rare to find this many unexploded bombs at once," said Maedomari.

"Because unexploded bombs from World War II are scattered across Okinawa, construction workers always use metal detectors before starting to dig the ground," he said.

Unexploded bombs are periodically found across Japan, even in highly developed Tokyo, but cases of injury-causing detonation are rare.

Okinawa was the bloodiest battle of the Pacific war, with US forces unleashing an 83-day air and amphibious assault dubbed by locals the "Typhoon of Steel". Some 190,000 Japanese died, half of them Okinawan civilians.

In January last year, a Japanese worker was severely injured when a World War II bomb exploded in Itoman city.

An estimated 10,000 tonnes of unexploded munitions were left in Okinawa after the war. About 4,500 tonnes remained by the time the United States returned Okinawa to Japan in 1972.

Since then, Japan's armed forces have disposed of another 1,500 tonnes, but it is expected to take 80 years or more to remove the rest.