San Francisco, Aug 29 (IANS): Two US soldiers were killed and three others injured in a helicopter crash during a training exercise in Southern California, military officials said.

The Blackhawk helicopter crash took place on the San Clemente Island, about around 112 km west of San Diego, Xinhua news agency quoted a Defence Department official as saying to the San Diego Union-Tribune on Friday.

The soldiers were assigned to the US Army's Special Operations Command and were conducting routine training, the newspaper reported, citing a statement from the US Army.

"We are still in the process of making next of kin notifications and will not release any additional information until that process is complete," J. Elise Van Pool, a US Army spokeswoman was quoted as saying by the paper.

Officials said that an investigation is underway to determine the cause of the accident.

This is the second fatal accident during military training exercises in the area in a month.

On July 30, nine US troops were killed when their amphibious assault vehicle sank near San Clemente Island.