A Japan Air Self-Defense Force transport aircraft has made an emergency landing at Niigata Airport in central Japan after a cockpit window slid open during flight. There are no reports of injuries or major damage.

ASDF officials said on Thursday that the C2 transport aircraft was on a training flight after taking off from Iruma Air Base in Saitama Prefecture, near Tokyo. The cockpit window suddenly opened around 5 p.m. The twin-engine plane made an emergency landing shortly after.

The officials said eight crew members were on board but they were not injured. They also said there are no reports of anything falling from the aircraft.

The ASDF is looking into the cause of the accident.

Niigata Airport temporarily closed its runway but resumed its use at 5:20 p.m.

Several accidents involving the Self-Defense Forces have occurred in recent weeks. A patrol aircraft overran a runway after landing at a Maritime Self-Defense Force air base in Chiba Prefecture on Wednesday.

Last month, two MSDF patrol helicopters collided in mid-air. One of the eight crew members was confirmed dead. The seven others have yet to be found.