A Royal Marine commando was killed in action yesterday when his river patrol was ambushed in southern Iraq.

Several others were injured in the attack, on the Al Faw peninsula, which came as the Marines launched their biggest offensive of the war so far on the suburbs of Basra, a few miles to the north.

A clutch of senior Iraqi army officers, including a brigadier general, were captured.

The marine was killed when his craft came under grenade and gunfire attack.

The ambush occurred as 539 Assault Squadron Royal Marines continued clearing the waterways on the peninsula, where Iraqi resistance is still holding out in pockets. A rocket attack on Kuwait City on Friday was launched from the area.

Two landing crafts were checking the river. When they came to a "Y" junction, the first craft continued forward, taking one of the branches of the river. The second, which had halted, came under gunfire, David Sharrock of The Times reported in a pooled despatch.

It retreated immediately out of the firing zone. As the second craft returned to give support, it came under a sustained attack from the riverbank.

The wheelhouse was struck by a rocket-propelled grenade and heavy machine gun rounds, seriously injuring three marines.

Another Marine was thrown into the river as the craft began to spin and a comrade dived in to rescue him. That left just a corporal to regain control of the craft as the Iraqis continued to fire.

The corporal, with no thought for his own life, reached the badly damaged wheelhouse and dragged his comrades to safety behind a bulkhead.

He then drove the craft out of the area, attempting to return to recover his comrades in the water, but was driven back by the intense firing.

They were later recovered from the water unharmed. The injured Marines were taken to the nearest medical aid unit and given emergency assistance then helicoptered to a field hospital.

One of the injured was saved by his flak jacket - a ceramic plate insert bore a direct hit. But one of the most seriously hurt later died from his injuries.

The Ministry of Defence in London said his next of kin had been informed.

An officer said of the corporal who rescued his comrades: "There is no doubt about it, what this corporal did was outstandingly brave.

"It is a tragedy that a Marine died but undoubtedly there would have been more fatalities without this corporal's actions."

The ambush occurred as a full-scale British offensive was launched on the southern suburbs of Basra.

Operation James, named after James Bond, saw up to 1,000 troops involved after heavy artillery pounded the area in a huge bombardment throughout the night.

By mid-morning, about 30 Iraqis were dead, including a Republican Guard colonel, and among hundreds captured was an Iraqi general.

Further north, thousands of US troops were last night braced for battle in Najaf, a key city south of Baghdad, as Iraq warned that 4,000 Arabs suicide attackers had arrived in the country and were ready to die.

Meanwhile, the US commander in the Gulf, General Tommy Franks, acknowledged the war could drag on for months.

Asked if it might stretch into the summer, he said: "One never knows how long a war will take."

British Defence Secretary Geoff Hoon said UK troops would be replaced if the conflict went on for months.

"They can certainly stay there for months, and there has never been any doubt of that.

"But clearly, ultimately, they would have to be replaced if that was such a long conflict."

31/03/2003