Four Marines Killed in Accident at Camp Pendleton

Were clearing up exercise range

Four marines have been killed at a military base in California while clearing an exercise range of unexploded devices.

The sweep for explosive material took place at about 11am on Wednesday at Camp Pendleton in San Diego during a routine maintenance operation.

That usually involves the detonation of ordnance, officials said.

An investigation was launched and no further details have been released.

The identities of the dead were being withheld pending notification of relatives.