A marine has died and eight are missing after a training mission went wrong off the coast of Southern California.
Search and rescue efforts are underway to find the missing men with support from the Navy and Coast Guard in the US.
Two other marines were also injured in the mission which took place on Thursday.
All are assigned to the 15th Marine Expeditionary Unit (MEU).
The MEU has a command element, a reinforced infantry battalion, a composite helicopter squadron and a combat logistics battalion.
The 15th MEU is currently based out of the Marine Corps Base Camp Pendleton in California.
Colonel Christopher Bronzi, 15th MEU commanding Officer, 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."