A US military helicopter has crashed in the grounds of a university on the southern Japanese islands of Okinawa.
Officials said at least three crew members were injured in the accident, which occurred in the city of Ginowan.
Some 20 people were reportedly in the building at the time - it is currently university summer holidays.
About 26,000 of the 48,000 US military personnel in Japan are stationed in Okinawa - an arrangement which often provokes controversy in the area.
The US military confirmed the crash in a statement, but gave no details expect that they were investingating the accident and that there were no reports of civilians casualties.
A fire department official in Ginowan said the injured people were all conscious but could not comment further. They have all been taken to a US military hospital.
Witnesses said that the CH-53 helicopter grazed had one of the university buildings before crashing into the ground and catching fire, according to Atsuhiko Kawano, a spokesman for Japan's Defense Facilities Administration Agency.
The CH-53 is used by US Marines for transporting equipment and supplies.
Many in Okinawa resent hosting the US troops. It is Japan's poorest province, and the string of tiny islands account for less than 1% of the Japanese landmass.
Such resentment has been fuelled by a number of criminal cases involving US servicemen in recent years.
In 1995, the rape of a local schoolgirl by three US servicemen triggered outrage throughout Okinawa.