World War II bomb wounds Okinawan worker

TOKYO, Japan (CNN) - A worker was severely injured Wednesday when a bomb, believed to be left over from World War II, went off at a construction site in Okinawa, police said.

The impact of the explosion in the city of Itoman damaged nearly 100 windows in a nursing home near the site and wounded a 75-year-old resident, said Osamu Hamada of the city's police force.

The worker - 25-year-old Jun Kohagura - was at the water supply construction site when the bomb exploded, injuring him in the face.

Authorities are looking into whether the bomb was left over from World War II. Several such unexploded bombs have been found in Okinawa, where more than 12,000 U.S. troops and 110,00 Japanese died in the last major battle of World War II.