EIGHT British troops - believed to have been Royal Marines - and four American servicemen were killed when their Sea Knight helicopter came down in Kuwait, it was confirmed today.

EIGHT British troops - believed to have been Royal Marines - and four American servicemen were killed when their Sea Knight helicopter came down in Kuwait, it was confirmed today.

The crash, which left no survivors, happened as the twin-rotor helicopter took part in deployment operations to the Al Faw peninsula in Iraq.

Lt Col Ben Curry, a Royal Marines spokesman in Kuwait, confirmed that the eight UK personnel were part of the 3 Commando Brigade.

The deployment was part of a mission by allied troops to capture an oil pumping station and pipeline.

Foreign Secretary Jack Straw today expressed "my personal, and the British Government's condolences to the family and loved ones of the service personnel who perished overnight in the helicopter accident".

Mr Straw, who is in Brussels, added: "This is an illustration of the risks which our very brave young men and women face when going into active service.'

Lt Col Curry said: "At 7pm GMT last night, combat units from 3 Commando Brigade Royal Marines in conjunction with Naval Special Warfare teams from the United States Navy launched a heliborne assault in the Al Faw peninsula in southern Iraq.

"The aim of the assault was to capture intact an oil pumping station and pipeline valve in order to prevent their destruction by Iraqi forces and the subsequent environmental pollution of the Persian Gulf.

"The mission has been successful. All objectives have been captured intact.

"Iraqi resistance has been light and there have been enemy casualties and prisoners.

"The combat units on the Al Faw peninsula are continuing to secure the area and more combat units from the 3 Commando Brigade are deploying.

"Regrettably, during the deployment phase, a US helicopter crashed. There were eight UK servicemen from 3 Commando Brigade and four US air crew on board.

"None survived the crash.

"There is no evidence that the helicopter crashed due to enemy fire. Our mission continues.'

He finished his statement by reciting the Royal Marine motto "Per Mare Per Terram' (By Sea, By Land).

The helicopter was assigned to the 1st Marine Expeditionary Force.

The Sea Knight fleet has a history of mechanical problems.

Last year, all 291 Sea Knights in US service were grounded after a crack was discovered in a rotor blade in one of them.

An American military source said the names of the casualties were being withheld pending next of kin notification.

The incident took place around nine miles south of the Iraqi border at 12.37AM UK time and followed a night of heavy bombardment of Iraqi positions.

A statement from US Central Command in Qatar said: "A US Marine Corps CH-46E Sea Knight Helicopter carrying both US and UK military personnel crashed early this morning south of Umm Qasr, near Highway 801 in Kuwait'.

It added: "The cause of the incident is under investigation.'