Rescue operations were underway Thursday for five US marines missing after two American military aircraft crashed during a refuelling operation off the coast of Japan, the Japanese defence minister said.
One crew member has already been rescued and is thought to be in a stable condition, Takeshi Iwaya told reporters.
A spokesman for the Japan Self-Defense Forces (SDF) said another crew member had been found but there were no immediate details of the marine's condition. "The Marine is being transported to a local hospital for evaluation," the US military said in a statement.
"US military and the Japanese Self-Defense planes and vessels are searching for those still missing... I hope all the members will be rescued safely as soon as possible," Iwaya added.
The marines were conducting "regularly scheduled training" when the crash occurred around 2:00 am local time, the 3rd Marine Expeditionary Force said in a statement.
The F/A-18 fighter jet with two crew onboard and a KC-130 refuelling tanker with five crew crashed into the sea around 100 kilometres off the cape of Muroto in southwestern Japan, Iwaya said.
The crew member rescued had been in the fighter jet, the minister confirmed.
Japan's SDF had deployed nine aircraft and three vessels for the search, he said.
"We are thankful for the Japan Maritime Self-Defense Force's efforts as they immediately responded in the search and rescue operation," the Marines said.
A spokesman for the Japanese coastguard said six vessels and an aircraft had been dispatched separately to assist in the rescue efforts.
There are few details about the circumstances of what the Marines described as a "mishap" and an investigation is underway.