Japan's Defense Ministry says two of its Maritime Self-Defense Force helicopters appear to have crashed late Saturday during nighttime training off the Izu Islands in the Pacific Ocean.

One of eight occupants was rescued, while the Self-Defense Forces are continuing their search for the remaining seven.

Officials say both aircraft, each carrying four people on board, are believed to have crashed. They say the condition of the rescued individual has yet to be confirmed.

Speaking to reporters, Defense Minister Kihara Minoru said the aircraft are believed to have crashed given that parts of the aircraft were confirmed at sea.

Ministry officials say communication with one of the helicopters was lost off Torishima Island at around 10:38 p.m., and one minute later an emergency signal was received from this aircraft.

They say about 25 minutes after this, at around 11:04 p.m., they realized that communication with the other aircraft was also lost in the same area.

The SH-60K helicopters are mainly stationed on and operated from destroyers. The two aircraft were engaged in night-time training to search for submarines.

The MSDF says as there were no other aircraft nor vessels in nearby waters, and involvement of another country in the incident is unlikely.