MANILA — Philippine workers at a swimming pool site stumbled on a mass grave containing 14 skeletons believed to be prisoners of war from the Japanese occupation in World War II, police said Sunday.

Police cordoned off the area in Nasugbu town, about a three-hour drive south of the capital Manila, shortly after the workers discovered the remains Friday.

"Further investigation disclosed that the said site was a former Japanese garrison during World War II and the residents there believed that the recovered skeletal remains were victims of war," police said in a statement.

A forensic investigation was being carried out to determine the nationalities of the victims, although they are believed to be Filipinos, police said.

The Philippines, a former US colony, fell to Japanese control in 1942 during World War II, and the three-year occupation is considered to be one of the darkest periods of the country's history.

Thousands of Filipino and American soldiers died during the occupation, many of them starved to death in Japanese garrisons around the country, historians said.

US General Douglas MacArthur, supreme commander of allied forces in the Southwest Pacific, eventually returned to retake control of large parts of the Philippines until Japan formally surrendered in 1945.