Six hundred forty blank gun cartridges have been found on a shore in the city of Okinawa.
Police said Saturday that a man found the blanks, some in a cardboard box and some scattered in the sea, on Friday and reported his finding to police on Saturday. Officers collected the cartridges by noon that day.
Police gathered 388 9mm cartridges and 252 12-mm cartridges. They were not used and are relatively new.
No Japanese or U.S. military practice areas are near the central Okinawan site.
Police will ask U.S. and Japanese forces at the beginning of the week whether such blanks are used on their bases.