A U.S. military helicopter made an emergency landing Friday evening in Okinawa, local government and police officials said, the second incident involving U.S. aircraft in just over a month in Okinawa, where public opposition to the huge U.S. military presence is strong.

The chopper was an AH-1 attack helicopter based at the U.S. Marine Corps' Air Station Futenma in Okinawa, a Defense Ministry source said.

The chopper landed in an attempt to avoid an accident after developing mechanical trouble, according to a central government source. The helicopter "conducted a precautionary landing," the U.S. Marines Corps said in a statement, adding, "There was no damage to the aircraft and no injuries."