Japan has asked the U.S. military to investigate the dumping of two fuel tanks by an F-16 fighter jet before it made an emergency landing at an airport in Aomori Prefecture, officials said Wednesday.

The U.S. fighter jet landed at Aomori Airport at around 6:10 p.m. on Tuesday. While there were no reports of injuries, at least one of the two fuel tanks apparently landed in a residential area in the prefecture, as police spotted bits of metal and liquid believed to be fuel about 20 to 30 meters from some homes.

The 35th Fighter Wing of the Misawa Base said that an F-16 fighter jet experienced a problem during a flight and its pilot jettisoned the fuel tanks into an unpopulated area close to Mount Iwaki in Aomori Prefecture.