SAN DIEGO -- Eight Marines were rushed to a San Diego burn centre and seven others were also hospitalized after their amphibious vehicle caught fire during a training exercise at a military base.

Three of the Marines were listed in critical condition Wednesday afternoon at the Burn Center at the University of California San Diego Health and five were in serious condition, the Marine Corps said in a statement. Four other Marines were rushed to the University of California Irvine Medical Center in nearby Orange County, including two in critical condition there.

Another Marine at a hospital in the San Diego suburb of La Jolla was in stable condition and two others were treated for minor injuries at a Navy hospital at Camp Pendleton.

"Our thoughts and prayers are with the Marines and their families affected by this incident," a Marine Corps statement said.

The Marines from the 1st Battalion, 1st Marine Regiment and 3rd Assault Amphibian Battalion were conducting a combat readiness evaluation as part of their battalion training at about 9:30 a.m. on a beach at Camp Pendleton Marine Corps base, north of San Diego, when the amphibious vehicle ignited, said Marine 1st Lt. Paul Gainey.

The amphibious vehicle got stuck and then caught fire as the Marines were trying to free it, said a defence who spoke anonymously because the official was not authorized to discuss the incident publicly,

The command is investigating the cause of the incident. Gainey said he had no further information to release.

The armoured vehicle is used to carry Marines and their equipment from Navy ships onto land. It resembles a tank and travels through water before coming ashore. It has been used in the Marine Corps since the 1970s.

In 2013, a 21-year-old Camp Pendleton Marine died and four others were injured when ordnance ignited an amphibious assault vehicle during a training exercise at Marine Air Ground Combat Center Twentynine Palms, in the California desert.

The Marine Corps has since developed a safer mine clearing system for its amphibious assault vehicles.

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Associated Press writer Lolita Baldor in Washington contributed to this report.