They will never forget the sound of the guns: a cross between a moan and a roar, a fierce rattling of 30mm cannon-fire from two A-10 Thunderbolts flying low overhead. The aircraft shouldn't have been in the British-controlled area – they were "cowboying" at just 500ft looking for something to have a crack at.

Last Friday morning, two American pilots turned their guns on a convoy of five British vehicles from the Household Cavalry, killing one man just three days shy of his 26th birthday, injuring four others and wiping out two armoured reconnaissance vehicles from the squadron's Two Troop. Two Iraqi civilians, waving a large white flag, were also killed.

Coloured smoke signs were sent up to indicate that they were friendly troops but it didn't stop the attack. The planes came back a second time, seriously injuring those who had managed to scramble out with only superficial wounds. The gunner Matty Hull, however, was the victim of a direct hit into his gun turret.

The men in the Scimitars were screaming over the radio "stop the friendly fire, we are being engaged by friendly fire" and "pop smoke, pop smoke".

The forward air-controller, who liaises with Allied air forces to bring in fire missions, was shouting "check fire, check fire". Frantic calls were made to 16 Air Assault Brigade headquarters to find out what was going on. No one seemed to know.

The A-10s were about to take a third swing when they were told by the US air patroller working with the Household Cavalry to stop firing. And instead of giving air cover while helicopters came in to evacuate casualties, they baled out.

The attack took place within the Household Cavalry's battlefield control line which means that everything in the air should be controlled by them and their embedded US air controller. The A-10s were well out of their own area and the matter is being investigated amid calls from some of the British troops involved that the pilots be prosecuted for manslaughter.

One of those injured in the attack, Lance Corporal of Horse Steven Gerrard, 33, said yesterday: "He [the pilot] had absolutely no regard for human life. I believe he was a cowboy. There were four or five that I noticed earlier and this one had broken off and was on his own when he attacked us. He'd just gone out on a jolly. I'm curious about what's going to happen to the pilot."

The two Scimitars had been proving a road, checking for landmines, enemy locations, assault batteries.

Amid the grief, the British anger could not be contained. All of D Squadron's vehicles are marked, with fluorescent panels on the roofs, flags and other markings. It was something the soldiers kept repeating.

"We spend all this money marking out our vehicles so this doesn't happen," one said, and "as far as I am concerned, those two pilots should be done for manslaughter."

Trooper Joe Woodgate, 19, the driver of the Scimitar in which Corporal Hull was killed, walked away with holes in his bullet-proof vest and a tear in either side of his shirtsleeve where shrapnel entered and exited, without touching his arm. All the rest of his colleagues had to be evacuated to the hospital ship Argos.

"I didn't realise that it was the Americans that had hit us. I thought we had been contacted by an Iraqi T-55 tank or something hiding out in the village," he said. "That gun, I don't want to ever hear that again. It's like a cross between a moan and a roar it's that fast."

The Pentagon's top general has expressed regret for deaths of British troops killed by US "friendly fire", saying work is under way to avert such errors.

Submitted by, Samantha