A US military aircraft and fighter jets made a series of emergency landings this week on an island in Japan's southernmost prefecture of Okinawa as well as in northeastern Japan, the country's defence ministry said on Wednesday (7 June).
The incident took place on Tuesday and involved the accident-prone US Marine Corps Osprey aircraft and three F/A-18 fighter jets.
The tilt-rotor aircraft made the emergency landing at the Ie Jima Auxiliary Airfield, near Okinawa's main island, after an emergency warning light flashed in the cockpit.
The jets landed at the Japanese Air Self-Defense Force's Matsushima base in Miyagi Prefecture after one of them notified of engine trouble, the ministry said.
No injuries were reported and the plane itself was not damaged, local media reports said. The US military was cited as explaining that the incident was a preventative measure.
The Osprey was based at US Marine Corps Air Station Futenma in Okinawa, while the fighter jets were heading to Iwakuni air station in Yamaguchi Prefecture from Alaska.
The emergency landing of the Osprey is the latest incident to come under criticism by Okinawa residents, who have been agitated with accidents linked to the US bases.
Okinawa hosts the bulk of US military facilities in Japan.
The Osprey, which has both vertical takeoff and landing capabilities, is designed to take off like a helicopter and rotate its propellers to fly like a plane. It has suffered a series of accidents in other parts of the world and due to its poor safety record the aircraft are reported to be abhorred especially in Okinawa.
"It's extremely deplorable we've seen these things occur one after another," an Okinawa government official told a news briefing.
Accidents involving Osprey aircraft
Local fears about the Osprey's safety increased following the crash landing of an MV-22 Osprey aircraft off the coast of Okinawa in December 2016. The incident forced Japan to call on the US to ground the Osprey aircraft in the region.
It was reported to be the first accident involving an Osprey aircraft in Japan since its deployment in the country in 2012, but it marked the second crash of a Marine aircraft in the region in less than one week. On 7 December, a US Marine Corps F/A-18C Hornet went down in waters some 250km southeast of Iwakuni, Japan, killing its 32-year-old pilot, Captain Jake Frederick.
The planes' safety raised serious concerns and questions even prior to the accidents recorded on the Japanese islands.
In May 2014, an MV-22B Osprey crashed in Hawaii, leaving two people dead and 20 others injured.
In August 2013, four crew members narrowly escaped injuries when the aircraft made a "hard landing" near the Creech Air Force Base in Nevada, China's Xinhua news agency reported.
In a single accident in 2000, 19 Marines lost their lives in Arizona during the Osprey's developmental phase. Eleven more people died in two separate crashes in the same year. The incidents prompted the launch of the plane's checkered safety record.