Four teens have been arrested on suspicion of vandalism at a cave in Okinawa Prefecture where civilians were forced to commit mass suicide in the closing days of World War II, police have said.

The boys, between the ages of 16 and 19, have admitted to destroying two signboards and origami paper cranes left by visitors to the Chibichirigama cave in the village of Yomitan between Sept. 5 and last Tuesday, investigators said Friday.

During the Battle of Okinawa, which started on April 1, 1945, with the landing of U.S. forces on the island, more than 80 Okinawa residents were believed to have committed suicide in the cave after taking refuge there.

Similar cases of mass suicide occurred at other locations during the battle, although exact data is unavailable.

Family members of those who killed themselves at the site during the war discovered the damage last Tuesday and reported it to authorities.

The four emerged as suspects after investigators checked security camera footage and interviewed neighbors, the police said.

Norio Yonaha, 63, who lost five members of his family in the mass suicide and is head of a group of bereaved families, told reporters that the vandalism was “an insult to the people who died” there.

Bottles and vases left by the wartime civilian victims were also found to have been damaged.

Some 94,000 civilians, or about a quarter of local residents, died in the three-month-long ground battle in Okinawa between Japanese forces and U.S. troops. Overall, more than 200,000 lives were lost, including those of Americans.

KEYWORDS Okinawa, WWII, history, vandalism, police