The bodies of four people believed to be crew members of a Japanese air force jet that went missing in mountainous terrain were found by rescuers on Thursday, officials said.

The bodies of four people believed to be crew members of a Japanese air force jet that went missing in mountainous terrain were found by rescuers on Thursday, officials said.

None have been publicly identified and a search for two other crew members and the aircraft continues.

The defense ministry spokesman who confirmed the discovery had no other details, but media reports said that metal fragments were also found in the search area in southwestern Japan.

The U-125 aircraft left a military base in Kagoshima prefecture on the island of Kyushu Wednesday afternoon and later "disappeared from radar", officials said.

About 600 rescuers, including troops and fire fighters, resumed searching for the plane in mountainous terrain near the base early Thursday.

But the rescue operation was suspended that afternoon due to bad weather, the spokesman said.

Public broadcaster NHK has showed footage of helicopters searching forest-covered mountains for the aircraft.