Thirty-two “blue-on-blue” attacks on British and other coalition vehicles have been logged in the past twelve months in southern Iraq, Britain’s area of responsibility.

The training was revealed as Washington and Rome announced a joint inquiry into the killing last week of an Italian secret agent when US troops opened fire on the car in which he was accompanying a freed hostage to Baghdad airport.

The inquiry was announced by General George Casey, commander of multinational forces in Iraq, after Gianfranco Fini, the Italian Foreign Minister, had highlighted differences between the American and Italian versions of the incident.

Nicola Calipari, an experienced hostage negotiator, was killed as he protected Giuliana Sgrena, a journalist, who had been held for a month.

On the same day, a 30-year-old Bulgarian machinegunner was shot and killed in a second friendly fire incident, for which US forces were also blamed.

The vast majority of the 32 reported incidents involved American troops opening fire at night-time against suspected insurgents who turned out to be friendly forces, on or near the main route through southern Iraq used by US convoys.

Military officials in Basra, where the British-controlled Multinational Division (Southeast) is based, said that the “vehicle blue-on-blue incidents” in the period from February last year had resulted in ten minor injuries. “There have been no fatalities,” one said.

The officials declined to spell out the injuries received or whether they were all British soldiers, but they confirmed that most of the “firing nationalities” were American. A small number of incidents involved Romanian and Bulgarian troops opening fire.

US commanders were so worried that their men were shooting at the British because they failed to recognise the Union Jack or other distinguishing military markings that, in an unprecedented move, they asked the British Army to supply vehicles, men and flags to teach their soldiers what their allies looked like.

It is understood that the British supplied several “snatch” armoured Land Rovers, the most common vehicle used by British troops on patrol and senior non-commissioned officers, with Union Jacks, to instruct the Americans.

This was in addition to a detailed presentation already provided by the British for all incoming US troops, which outlines what a British soldier looks like, what type of vehicle he drives and what other coalition troops in southern Iraq drive around in.

When asked by The Times about the special anti-fratricide training, which was requested in January, a spokesman for US Army Forces Command at Fort McPherson in Atlanta, Georgia, said: “It is understandable we are doing this. We all want to reduce the number of friendly fire incidents. Checkpoints are very dangerous places. It has come into the headlines with the Italian and Bulgarian, but there are more incidents that do not get publicity and probably do not end so badly.”

British troops have been given warning against approaching American convoys because of the risk of being shot at. They are ordered to slow down to a snail’s pace as they pull alongside a convoy. They are told to display the Union Jack and shout that they are British. “The problem is that most of these incidents happen in the dark,” a military source said.

A British officer in Basra said: “The Americans can be pretty pumped-up. Sometimes they fire in broad daylight when we are travelling at two miles per hour, shouting that we are British out of the window and waving the Union Jack. If they shoot, our drill is to slam on the brakes and race in the opposite direction.”

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