A metal panel flew off a Japanese government plane Thursday while it was en route from Tokyo to Hokkaido, the Air Self-Defense Force said.

The panel was one of several connecting the right wing to an engine of the Boeing 747, but operational safety was not affected, the ASDF said, adding there were no reports of injuries.

According to the ASDF, which is in charge of operating government aircraft, the plane left Tokyo's Haneda airport around noon Thursday after maintenance and arrived at New Chitose Airport in Hokkaido at around 1:10 p.m.

After arrival, ASDF crew members found that a 38-cm by 20-cm panel weighing about 0.5 kg had disappeared. The panel was in place during a visual inspection of plane at Haneda.

The jumbo jet is a backup plane for the on that will carry Prime Minister Shinzo Abe on a tour of the Baltic and southwestern Europe starting Friday.

Government planes, which are mainly used to transport the Emperor and Empress in addition to the prime minister, are based at the ASDF's Chitose base.