TOKYO, Dec. 13 (Xinhua) -- The U.S. forces in Okinawa said on Wednesday that a window fell from a military chopper, according to prefectural officials in Japan's southernmost prefecture.

Local authorities confirmed that an object fell from the chopper and onto the grounds of an elementary school in Ginowan, Okinawa.

Prefectural authorities said they were notified by the U.S. forces in Okinawa that a window had fallen from a CH-53E transport helicopter.

An object measuring 1 meter-square in diameter reportedly fell onto the school located in Ginowan, at around 10:15 a.m. local time.