A US Marine has died and eight other service personnel are missing after a "mishap" involving an amphibious assault vehicle off the coast of southern California.
According to a statement by I Marine Expeditionary Force, two personnel were also injured in the incident which happened on Thursday, with one admitted to hospital in critical condition and the other in stable condition.
The personnel travelling in the amphibious assault vehicle from the shores of San Clemente Island to a Navy ship when they reported that the vehicle was taking on water.
The US navy-owned island is about 70 miles offshore from San Diego.
Military ships and helicopters were searching choppy seas for the missing amid moderate to strong winds.
All involved in the incident were assigned to 15th Marine Expeditionary Unit, the statement on Twitter said.
Colonel Christopher Bronzi, Commanding Officer of 15th Marine Expeditionary Unit, said: "We are deeply saddened by this tragic incident.
"I ask that you keep our Marines, Sailors, and their families in your prayers as we continue our search."
The Marine Expeditionary Force is the US Marine Corps’ main war fighting organisation.
It consists of three such groups, made up of ground, air and logistics forces.