A roadside bomb killed 14 Marines and their civilian interpreter yesterday, one of the deadliest single strikes on an armoured vehicle in the war.

The Marines, who were killed just outside the town of Haditha on the Euphrates river, were from the same Ohio battalion that lost six other Marines in combat on Monday. Some of the victims had their throats cut, according to an al-Qaeda-linked terror group. The Islamist organisation, Ansar al-Sunna, said it was holding a wounded Marine. The claim was denied by the Pentagon.

The Marines killed yesterday died when their amphibious assault vehicle struck a roadside bomb during an operation against guerrillas who had killed their six comrades on Monday. A seventh Marine was killed the same day by a suicide bomber.

There are an estimated 25,000 Marines in al-Anbar province, the tribal region that makes up the bulk of the dangerous area known as the Sunni Triangle. They have been deployed in almost constant, large-scale operations in recent months to try to prevent foreign Islamist fighters from slipping across the Syrian border and moving down the Euphrates valley to hotspots such as Ramadi, Fallujah and Baghdad.

Ansar al-Sunna, one of the most radical militant groups in Iraq, said in an internet statement that it had killed eight US Marines and captured a ninth on Monday. It added that a ninth Marine “who was wounded in an ambush . . . near Haditha” had been captured, and promised to publish pictures of the prisoner.

US defence officials have admitted that the six Marines killed on Monday were snipers, working on foot and in two separate teams. Witnesses in Haditha said that masked gunmen later came to the market to show helmets, flak jackets and other equipment they said were from the Americans.

The body of one of the six, initially listed as missing, was later found more than a mile away from the ambush site, according to US press reports. The Pentagon said he may have been dragged away by the guerrillas.

All 20 men were reservists from the same unit, the 3rd Battalion, 25th Marines, based in a suburb of Cleveland, Ohio. One was identified by relatives as Lance Corporal Jeff Boskovitch, 25, a police officer who was due to marry when his tour of duty finished in the autumn.

COMBAT DEATHS

• 1,811 US soldiers killed since 2003 invasion
• Worst month: November 2004. 137 killed
• 486 US deaths since January 1, 2005
• 67 killed in July 2005 Sources: US Central Command, Iraq Coalition Casualty Count

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