6 U.S. Personnel Dead in Southern Afghan Chopper Crash

Six U.S. service personnel were killed in a helicopter crash in southern Afghanistan on Thursday, officials said, indicating the incident was not believed to be the result of enemy fire.

The helicopter, a CH-53 Sea Stallion, went down in the volatile Helmand province, according to one U.S. official who said: "Initial indications are that this was not hostile fire."

The dead were members of the U.S. military, another U.S. official told Agence France Presse.

In a brief statement, NATO's International Security Assistance Force said the cause of the crash was "under investigation."

"However, initial reporting indicates there was no enemy activity in the area at the time of the crash," it said.

The Sea Stallion is a heavy transport aircraft capable of carrying about 40 people. The U.S. officials did not say whether anyone else was on board, other than the six victims.

An ISAF spokesman told AFP in Kabul that the crash occurred late on Thursday local time.

He stressed that "there was no enemy around," but could not give further information such as the terrain at the crash site or the weather.

In August, 30 U.S. troops were killed when Taliban insurgents shot down a U.S. Chinook helicopter, in the most deadly incident for U.S. and NATO forces since the war in Afghanistan began in 2001.

The dead included 17 Navy SEALs and five other Navy sailors assigned to the SEAL unit. Seven Afghan troops and an interpreter were also killed.

Most of the Navy commandos came from the same SEAL team credited with killing al-Qaida leader Osama bin Laden in a May raid in Pakistan.