A United States Air Force F-16 Fighting Falcon accidentally dropped an inert bomb on private land outside training grounds in Aomori Prefecture, north of Japan’s main island of Honshu.

The aircraft belonged to the 35th Fighter Wing, stationed at the US Misawa Air Base, on the main island of Honshu. It was on a training flight when it released the device, 5 kilometers (3 miles) off from its intended location in the Draughon training range. The dummy bomb fell on a private land but did not do any damage or injuries.

The authorities of the Aomori prefecture expressed concern, as schools are located near the area where the 500-pound (226-kilogram) dummy bomb fell. The Japanese defense ministry lodged a complaint with the U.S. military over the incident. “The dropped object is quite heavy and it must not happen. We will ask to take effective measures to prevent similar incidents from happening again,” Chief Cabinet Secretary Yoshihide Suga said at a press conference, quoted by Kyodo News.

The U.S. Army bases in Japan are frequently subject to protests from the population of the island. After several incidents, the safety of the U.S. presence is being questioned.

On December 13, 2017, a window fell from a U.S. Marines CH-53E transport helicopter on a school, injuring a 10 years old boy.

On June 11, 2018, a United States Air Force F-15C fighter crashed off the island of Okinawa, South of Japan. The pilot managed to eject. The incident had sparked heavy criticism from the local government, which questioned the safety of the presence of the base.

While some islanders have asked for a complete dismantlement of the U.S. presence on Okinawa, the governor, backed by Japanese Prime Minister Shinzo Abe, supports the relocation of Kadena Air Base to a less populated part of the island.