There has been another suicide bomb attack on the Black Watch battle group near Camp Dogwood in Iraq.
The Queen's Dragoon Guards are part of a 850-strong battle group
A car exploded at a checkpoint manned by six Queen's Dragoon Guards, killing the car's driver, but the Ministry of Defence said no UK soldiers were hurt.
A BBC correspondent said a soldier was earlier injured after driving a Warrior fighting vehicle over a buried bomb.
He said the UK soldier had been flown to hospital in Baghdad but his injuries were not said to be life-threatening.
It is the first serious combat injury faced by the Black Watch for more than a week.
From Camp Dogwood correspondent David Loyn said the suicide attack happened in the far west of the region patrolled by the battle group.
He said the Queen's Dragoon Guards had been working there since their deployment in the area, south-west of Baghdad, began.
"They stopped two cars and when they approached the first, the second detonated," he said.
A military spokesman, Capt Stuart MacAulay, said: "This is why we're here - to stop these people.
"There is always said to be an element of luck in any operation, but the way we approach the vehicles is why these soldiers are still alive."
David Loyn said the incidents were the first serious attacks on the Black Watch since a Fijian soldier serving with them was killed more than a week ago.
He said: "In the early days of their operation they suffered far more casualties before they refined their tactics to deal with the specific threat in this region.
"They've adopted a much more robust military posture using high explosive mortar shells and conducting fast-moving road blocks."
But he said there were fears of a renewed upsurge in attacks now that the Muslim religious festival of Eid had ended.
The 850-strong force has been attacked repeatedly since it took over from US forces at the base, 20 miles (32km) from Baghdad.
The regiment's deployment at Camp Dogwood, standing in for US troops, is due to end on 3 December.