Part of a US helicopter has crashed on a school in Okinawa, Japan, renewing tensions with the local population.
The window dropped on the school grounds, slightly injuring one boy, news agency Kyodo said.
The southern island of Okinawa hosts the largest US military presence in Japan.
Over the past years, a number of accidents and crimes have led to growing local opposition to the US base.
The US presence on Okinawa is a key part of the post-war security alliance between the two countries.
The Futenma base is located in a residential area, with schools, shops and hospitals. Residents have long been concerned over possible crashes or accidents.
The US government wants to move Futenma, the largest Marine base in Okinawa, to a more remote location on the island.
But the governor of Okinawa, Takeshi Onaga is leading a campaign to get the US military base off the island completely, reports BBC.