Four MV-22 Osprey aircraft flew on Monday to the Atsugi air base, which is jointly used by the U.S. Navy and the Maritime Self-Defense Force, in Kanagawa Prefecture for the third time amid local protests.

The tilt-rotor transport aircraft will conduct landing and takeoff drills from Tuesday through Friday at the Ground Self-Defense Force's training areas of Higashi-Fuji and Kita-Fuji in Shizuoka and Yamanashi prefectures, the Kanagawa Prefectural Government said.

The Ospreys are scheduled to pass through Atsugi base again on Saturday before returning to the U.S. Marine Corps Air Station Futenma in Okinawa Prefecture, the prefectural government said.

The Defense Ministry's South Kanto Defense Bureau has informed Kanagawa Prefecture that the Ospreys could fly to U.S. Naval Air Facility Atsugi again mainly for refueling purposes during the exercises.

The four Ospreys passed through U.S. Marine Corps Air Station Iwakuni in Yamaguchi Prefecture before coming to the Atsugi base on Monday.

The same day, about 150 local residents and supporters who brought to court their complaints about noise pollution near the Atsugi base gathered to protest the Ospreys' flight over a densely populated area.

The Ospreys' last flights to Atsugi took place on July 15 and 18, stopping by Camp Fuji in Shizuoka on both days. The Ospreys then flew from July 19 to 21 to the GSDF's Okadama camp in Sapporo to attend an aviation event there.

The Futenma base has 24 Ospreys, which can take off and land like a helicopter and cruise like an airplane.

The presence of Ospreys has sparked safety concerns among the people of Okinawa, which shoulders the bulk of U.S. military bases in Japan, due to a series of accidents overseas.

This has prompted Tokyo to urge Washington to conduct exercises using Ospreys outside Okinawa to alleviate the burden on the prefecture.