A commercial transport ship believed to be carrying an additional batch of the U.S. military aircraft Osprey left California on Tuesday for their deployment in Japan's Okinawa amid opposition by its governor due to safety concerns.
The Japanese Defense Ministry said earlier a group of 12 units of the tilt-rotor transport aircraft is expected to be unloaded at a U.S. Marine Corps base in Iwakuni in western Japan in the last week of July.
The commercial vessel, onto which a total of 12 Osprey airplanes were seen loaded Monday, departed a port in San Diego.
The 12 airplanes will join another 12 units already stationed at the Marine Corps Futenma Air Station in Okinawa next month at the earliest, replacing all aging CH-46 helicopters of the force.
The first batch of the 12 Ospreys also left the same port last year.
The U.S. military has said it plans to station a total of 24 Osprey airplanes, which can take off as a helicopter and fly as an airplane, at the Futenma base by 2014 aiming to enhance the operational capability in the Asia-Pacific region.
Okinawa Gov. Hirokazu Nakaima has opposed to the deployment of the aircraft in the southern island prefecture, which already hosts a bulk of U.S. military forces in Japan, due to its history of crashes.