EIGHT British servicemen died today when their American helicopter crashed in the Kuwaiti desert, British military officials confirmed.They were on board the CH-46 Sea Knight aircraft as part of the invading force of allied troops involved in seizing oilfields on the Al Faw peninsula - the first major operation in the invasion of Iraq.

EIGHT British servicemen died today when their American helicopter crashed in the Kuwaiti desert, British military officials confirmed.

They were on board the CH-46 Sea Knight aircraft as part of the invading force of allied troops involved in seizing oilfields on the Al Faw peninsula - the first major operation in the invasion of Iraq.

The American crew of four also died.

Lt Col Ben Curry, a Royal Marines spokesman in Kuwait, said: "Regrettably during the deployment phase a US helicopter crashed.

"There were eight UK servicemen from 3 Commando Brigade and four US air crew.

"None survived the crash."

The accident happened at 12.37am UK time, nine miles south of the Iraqi border.

Group Captain Al Lockwood, a spokesman for British forces in the Gulf, said: "It was an accident, I can confirm it was not brought down by enemy action.''

He said: "We are carrying out our own investigation. We have people at the crash site.''

The aircraft has a history of mechanical problems and last year all 291 Sea Knights in US service were grounded after a crack was discovered in a rotor blade in one of them.

The crash came as coalition troops pushed towards the Iraqi capital Baghdad and sought to secure Basra, the border port town of Umm Qasr and the strategic Al Faw peninsula on the Persian Gulf.

Royal Marines commandos stormed the Al Faw peninsula to capture key oil facilities.

Their lightning offensive began at about 7.25pm UK time yesterday with heavy artillery shelling before elite troops stormed numerous installations.

Six Iraqis were said to have been killed, 16 captured and one vehicle destroyed but there were no reports of any US or British casualties.

Some parts of the Al Faw complex had been set alight, but Group Capt Lockwood told PA News they had secured the oil facilities and were now moving up the Al Faw peninsula.

The troops met only "light resistance'' and suffered no casualties, he said, adding: "They have secured the beachhead and moved up along the peninsula to secure the oil infrastructure.''

In a separate offensive to the west of Basra, troops from the 7th Parachute Regiment Royal Horse Artillery helped US soldiers securing oilfields from possible sabotage.

Umm Qasr, south of Basra, was likely to be secured in the course of today, according to military officials.

Coalition forces in northern Kuwait were maintaining their heavy bombardment in the direction of the port.

British submarines also fired Tomahawk cruise missiles while RAF Tornados were used against military targets.

Securing Umm Qasr would set the stage for the capture of Basra, which lies just 20 miles from the Kuwait border.

Elsewhere on the ground, coalition forces were reported to be meeting little resistance as they pushed across the desert towards Baghdad.

The 7th US Cavalry in Abrams main battle tanks and Bradley personnel carriers were "charging to Baghdad'', in the words of CNN TV reporter Walter Rodgers, who is travelling with them.

After an initial skirmish with Iraqi troops when they burst out of Kuwait, the Apache and Crazy Horse troops of the cavalry raced across the desert at 25mph for hours without meeting any opposition.

Waiting to follow them was the 3rd Infantry Division.

However, Rodgers said the US troops were "realistic'' that they would have to fight nearer to Baghdad, particularly the Iraqi Republican Guard.

The apparent ease of their passage so far had been the "lull before the storm'', he said, adding: "Every soldier knows the way they're heading and their objectives and there will be a hard fight ahead.''

Some units, like the 1st Marine Expeditionary Force, have already met resistance.

The troops were pinned down by Iraqi anti-tank rockets and small arms fire just yards after crossing the border, according to BBC News 24's correspondent Adam Mynott.

He said the convoy he was in had been forced to retreat and it was unclear whether one vehicle had been hit. British artillery fire had been called in.

"We're now taking cover behind a sand bank,'' he said. "There is sustained gunfire coming from Iraqi positions.''

He added: "Resistance is stronger than had been expected.''

Commenting on the invasion of Iraq, Group Capt Lockwood said: "One division crossed the border last night and 3 Commando Brigade landed on Al Faw peninsula.

"They secured oil equipment on the peninsula so there would be no risk of oil pollution into the Gulf.

"There was limited contact (with the enemy) and no British casualties.

"There was light resistance.''

He would not be drawn on whether there were any any Iraqi casualties.

British troops were supported by artillery fire.

The Royal Marines made an amphibious landing and made quick progress, taking the beach and moving up to the oil facilities.

He said: "The other British land forces crossed the point of departure and have entered Iraq.

"UK submarines contributed cruise missiles against very important targets in Iraq.''

He said mine countermeasures were deployed by British ships to clear the waterways into the port of Umm Qasr.

He said: "The aim is to allow humanitarian assistance and shipping to get in.''

He added: "The RAF were involved in a wide range of operations.

"Tornados were used against military targets to shape the battle space.

"Harrier GR7s have also been involved in close air support missions to support land forces.''