But defence experts in Britain have warned the situation could spiral out of control.

People are still coming up to [the peacekeepers] and chatting to them - the reaction is still friendly

ISAF spokesman Jonathan Turner

"At around 2030 (1600 GMT Wednesday) a patrol from the second battalion, the parachute regiment, came under fire in western Kabul as they were dismounting from their vehicles to start a foot patrol," said ISAF spokesman Jonathan Turner.

Afghan police in the area as part of a separate patrol say they were also fired at.

Last Saturday, troops of the same regiment fired at an Afghan car, killing a young man and wounding four others, including a pregnant woman.

The British peacekeepers said they were responding to gunfire, but witnesses said the shooting was unprovoked.

'Lawlessness'

An investigation is currently under way and two of the paratroopers involved in the incident have been sent home.

On Thursday, shadow defence spokesman Bernard Jenkin said the exchange of fire was "inevitable" given the circumstances, and a robust response was necessary.

He said: "The clear message is that any factions that pick on peacekeeping forces can expect as good as they get."

But Major Charles Heyman, editor of Jane's Defence Armies, said: "There is a real chance the situation could deteriorate unless something is done."

The tower from where the soldiers opened fire on Saturday

He suggested paying the local police to bolster their support and prevent lawlessness.

Defence expert Mike Yardley, a former British Army officer, said: "The key to these sort of operations is winning the hearts and minds of the local population.

"At the moment I think the peacekeepers have the support of the people.

"They are glad to be rid of the Taleban but things could go awry very quickly if more trouble takes place."

Anger

The 4,000 troops of the ISAF have been sent by the United Nations to help maintain security in Kabul during the six-month term of the interim administration led by Hamid Karzai.

Mr Karzai has asked that the force be extended to other areas in the country while the country's army and police force were being built up.

But among Afghans, emotions towards the presence of foreign peacekeeping troops are mixed.

Relatives of the victim are angry

Nasser Yaqobi, the uncle of Hamayon Yaqobi, the man shot dead by the British troops on Saturday, told the Reuters news agency that the foreign force should leave Afghanistan.

"We feel very, very angry, and it is not just our family, it is everyone," he said.

But the ISAF spokesman said the foreign troops were being made welcome by the Afghans.

"People are still coming up to them and chatting to them. The reaction is still friendly in the main," he said.