The rescued marine was found alive 200 miles off the coast off the coast of Iwakuni approximately 9am local time (midnight GMT) by the Japanese Maritime Self-Defence Force. Search and rescue efforts are ongoing to find the aircrafts, along with the six missing military personnel. Lt. Col. Kelly Frushour of the 3rd Marine Expeditionary Force told NBC News: “We are still searching for six marines.”

The crash happened at 2am local time (5pm yesterday GMT) during regularly scheduled training, according to the Marine Corps.

The aircrafts had launched from Marine Corps Air Station Iwakuni, a US station in Japan.

A spokesman for the US marine corps said: “Search and rescue operations continue for US Marine aircraft that were involved in a mishap off the coast of Japan around 2am December 6.”

He added: “The aircraft involved in the mishap has launched from Marine Corps Air Station Iwakuni and were conducted regularly scheduled training when the mishap occurred.

“Japanese search and rescue aircraft immediately responded to aid in recovery.”

It is unclear whether US military officials are also assisting with the search.

An anonymous US official said that one of the aircrafts was an F/A-18 Hornet fighter jet.

The other plane was apparently a KC-130, an extended-range tanker refuelling aircraft.

Five marines were reportedly aboard the KC-130 Hercules and 2 flying the F/A-18 fighter jet, which was being refuelled.

Anonymous US officials said they were unsure how the mishap may have occurred, but none suspected foul play.

A crash may have occurred mid-air during the refuelling but this is unconfirmed.

Aerial refuelling with a KC-130 requires another aircraft to pull slightly below and behind it, with hoses extended from huge steel tanks on the KC-130’s wings to the aircraft needing fuel.

An investigation has been launched into the incident and the circumstances of the mishap.