A boy has been injured after a window from a US Marines helicopter fell on a school playing field in Japan – the second such incident in the past week.
The governor of the island of Okinawa stood stony-faced outside Daini Futenma Elementary School showing reporters a picture of the metal-framed window.
The boy is said to have suffered minor arm injuries in Tuesday’s incident.
It came from a Sikorsky CH-53E helicopter. Brought into service in 1981 and more than 30m long, it is the largest in the US military.
The Marines Corps, whose Air Station Futenma is next to the school, has apologised for the “regrettable” incident.
A smaller part, believed to be from another US military chopper, fell onto a kindergarten near the base last week but no one was hurt.
The Marine Corps said the latest aircraft to shed one of its parts had immediately returned to the base after the incident.
“We take this report extremely seriously and are investigating the cause of this incident in close coordination with local authorities… This is a regrettable incident and we apologise for any anxiety it has caused the community,” said a statement.
The incident could fuel opposition to the American base, which is located in a crowded residential area of central Okinawa.
A planned relocation has been delayed for more than 20 years and many locals want it off the island altogether.
There are about 54,000 US military personnel in Japan – more than in any other country – along with 42,000 dependants.
Tens of thousands are stationed on Okinawa – a relatively small island – and occasional crimes and bad behaviour by US military personnel and workers have led to tension.
Last month, American troops across Japan were banned from drinking alcohol after a Marine three times over the limit was involved in a crash that killed a local Okinawan man.