A part may have fallen off a US military aircraft stationed at Yokota Air Base in Tokyo during a training flight. So far there is no report of damage.

Tokyo officials say the Defense Ministry informed the Tokyo government and municipalities near the base on Wednesday that the US military found that a lens covering a wing light was missing from a C-12 transport craft after a flight the previous day.

Metropolitan government officials say the lens is about 25 centimeters long, 10 centimeters wide and weighs 1 kilogram.

Tokyo and the municipalities near the base believe the lens fell off during the flight. They say the incident could have caused a life-threatening accident.

They asked the US Air Force in Japan to find out what happened and take measures to prevent a recurrence. They also urged the US side to ground the plane until it takes preventive measures.