The U.S. Marine Corps in Okinawa said two more Osprey tilt-rotor aircraft arrived Saturday at the Futenma base from Iwakuni, Yamaguchi Prefecture.

The Ospreys, part of a batch of 12, were expected to fly out of Marine Corps Air Station Iwakuni on Saturday morning, but the U.S. military delayed their departure, saying requirements for the flight had not been met. It denied there were any technical problems with the aircraft.

The 12 Ospreys, which can take off and land like a helicopter and fly like an airplane, are the second batch to be deployed to Japan, following the arrival of the first dozen last summer.

The aircraft is replacing aging CH-46 helicopters in Okinawa, which hosts the bulk of U.S. military forces in Japan.

According to the U.S. Marines, two or more Ospreys were set to fly to U.S. Marine Corps Air Station Futenma on Saturday and the rest would follow soon.

Okinawa Gov. Hirokazu Nakaima has repeatedly called for the cancellation of the deployment in his prefecture due to the aircraft's history of crashes and other safety concerns.

About 200 people staged a rally Saturday morning, with about 60 of them taking part in a sit-in in front of the Futenma main gate to protest the Osprey deployment. Due to their actions, traffic in and out of the base was temporarily halted starting at around 7 a.m.

Local police removed the protesters at around 9:30 a.m. and arrested one man for obstructing officers in their duties after he grabbed an officer by the collar and tore buttons off his uniform.

The protesters moved to a site across from the gate.