A U.S. Marine Corps helicopter performed an emergency landing in Japan Wednesday before bursting into flames. The accident happened on the island of Okinawa outside a U.S. training facility. No one was hurt in the crash.

The incident heightened tensions in Okinawa, where some are upset about the U.S. military presence there. Around one-quarter of U.S. military facilities are in Okinawa, according to the Wall Street Journal Wednesday, and as of this summer, the island was home to 400,000 active service members, according to the Defense Department.

Okinawa Gov. Takeshi Onaga, called the crash “outrageous.” Onaga wants the U.S. military presence on his island reduced.

Japanese Defense Minister Itsunori Onodera has asked the U.S. military to “immediately investigate the cause, prevent a recurrence, thoroughly implement safety controls, and supply detailed information,” according to the New York Times Wednesday.

The Japanese government is investigating whether any civilians were injured while the U.S. military is investigating the cause of the incident. The helicopter was a CH-53.

Last month two Marine hybrid Osprey Marine aircraft had to make emergency landings at an airport in Okinawa and last December a Marine Osprey crashed off the coast of the island.