One helicopter between al Qaeda mastermind and escape

When British troops came close to capturing al Qaeda's top commander and the occupation forces' most wanted target in Iraq, the operation collapsed after the sole British helicopter ordered to monitor their prey ran out of fuel and had to return to base.

The blunder, in March 2005, probably allowed Abu Musab al-Zarqawi, a Jordanian associate of Osama bin Laden, an extra 15 months to expand al Qaeda's operations throughout Iraq, bringing the country close to civil war.

His fundamentalist Sunni supporters were behind some of the worst atrocities aimed at Iraq's Shiite majority population, as well as countless attacks on American and Iraqi government forces.

Their bombing of a sacred Shiite shrine in Samarra in February 2006 launched a wave of revenge killings that lasted for 18 months.

He was eventually located by the Americans in a house north of Baghdad in June 2006 and killed with his family by an American airstrike.

His apparent narrow escape from British troops and a unit of British special forces emerges from the secret military intelligence logs examined by the Observer. They report that on March 17, 2005, the G3 cell of Army intelligence at British brigade headquarters in Basra heard that Zarqawi, who had a US$25 million reward on his head, was travelling south on Route 6 from Amara to Basra. At 2.45pm, the report says, a Lynx helicopter spotted a suspicious car that had stopped 14km south of Qurna and about 95km north of Basra. The report says the helicopter maintained "top cover" for 15 minutes, but then had to return to the British-run Shaiba logistics base to refuel.

"As a result the area of interest was unobserved for between 20 and 30 min," the report adds. By then British troops from Corunna company of the 1st Battalion, the Duke of Wellington's Regiment had rushed in and set up an inner and outer cordon around the area. British special forces and an American "arresting officer" were brought in.

Having lost their helicopter cover, the forces were reduced to random searching. A mosque was raided, but civilians were the only people inside.

"At 22.14," the report ends, "the search was concluded."

Unlike many other reports in the logs, this one makes no comment on the source of the intelligence and its reliability. The British may have doubted it, since Amara is in an overwhelmingly Shiite area.

Zarqawi became friends with bin Laden when they were both resisting the Soviet occupation of Afghanistan in the late 1980s. Arrested in his native Jordan in 1992, he was convicted of trying to overthrow the monarchy. After the US-led invasion of Iraq, he aligned himself with al Qaeda and was recognised as its leader in Iraq.

- Observer