(Adds Marines to delay next delivery of Osprey aircraft)
TOKYO Aug 5 A U.S. military helicopter crashed on Japan's southern island of Okinawa on Monday, U.S. Forces in Japan said, an incident that could stoke anger over the concentration of U.S. military bases on the island.
The U.S. Air Force said in a statement that three of the four crew members involved in the crash were in stable condition. It said the remaining crew member had not been accounted for.
There were no casualties among local residents, a Japanese official said.
Video footage showed smoke rising from a fire on a remote mountainside.
The air force said an HH-60 helicopter, based in Kadena airbase in Okinawa, crashed in a training area on the U.S. Marines' Camp Hansen and U.S. fire and rescue crews were responding. It added that the helicopter was conducting a training mission at the time.
"This is really regrettable. We are asking the U.S. side for a speedy supply of information," Defence Minister Itsunori Onodera told reporters. "We plan to strongly demand for investigation into the cause of the accident and measures to prevent a recurrence."
Prime Minister Shinzo Abe wants to move the U.S. Marines' Futenma airbase to a less crowded part of the island, but stiff opposition from Okinawa residents is stalling the plan.
Residents of Okinawa, host to the bulk of U.S. military forces in Japan, have long resented bearing what many feel is an unfair share of the burden for the U.S.-Japan military alliance. Many associate the U.S. bases with accidents, crime and pollution.
The Marines said they would comply with a request to delay the next scheduled arrival of MV-22B Osprey aircraft "out of respect for the desires of our Japanese partners and hosts."
"The MV-22 is a highly capable aircraft with an excellent operational safety record, and we will resume their deployment to Okinawa in the near future," the Marines said in a statement. (Reporting by Tokyo bureau, additional reporting by Phil Stewart in Washington; Editing by Nick Macfie and Ken Wills)