At least 21 civilians, including six children, have been killed in US air strikes in Afghanistan, leading to angry protests among locals. The deaths brought the total of civilian deaths to almost 100 in the past two weeks and followed President Hamid Karzai's declaration that his people "can no longer accept casualties the way they occur".

The new round of "collateral damage" also came a day after the US military said it was "deeply ashamed" of the killings of 19 civilians by marines in early March.

In the latest incident American special forces called for air strikes in the village of Soro near Sangin in Helmand, after coming under attack from around 200 Taliban fighters.

A spokesman for the US forces, Major William Mitchell, declared that the troops had killed a "significant" number of insurgents in firefights and the subsequent bombing.

"We don't have any reports of civilian casualties" he said. " There are enemy casualties - I think the number is significant." However, this was immediately contradicted by the governor of Helmand, who said: "Nato forces carried out an operation in Sangin and as a result of the bombing 21 civilians, including women and children, were killed."

Mohammed Asif, a resident of the village which came under Nato aircraft fire, said: "I know at least five homes were destroyed, there may be up to 38 people killed and 20 more were wounded. Foreign and Afghan troops are stopping people from some of the roads getting here."

Another resident claimed that a number of bodies had been taken to the British base in Sangin in an attempt to prove that they were civilians and not Taliban fighters. However, there was no confirmation of this from the British forces.

Following the apology over the casualties in March, Nato's British spokesman Nicholas Lunt said yesterday: "We know that our ability to operate here in support of the government of Afghanistan is dependent upon the support of the people of Afgha-nistan. We know very well that civilian deaths and injuries undermine this goodwill and support."

Nato has announced that in future it will engage the Afghan government much more in planning military operations and keep it fully informed about developments. There is unease, however, among some Western commanders that information about previous offensives has been leaked to the Taliban from official Afghan sources.

Meanwhile, Afghanistan's senate called on President Karzai's government to open direct talks with the Taliban in an effort to bring the bloodshed to an end.

There have been unconfirmed claims that the reason the Afghan capital, Kabul, has not experienced a serious suicide bombing for several months is because of an unofficial agreement between the government and Gulbuddin Hikmatayar, one of the insurgent leaders.

Many MPs are now demanding that similar pacts should be sought with the "local Taliban" in many areas.

In a separate incident, four civilians were killed yesterday when a suspected suicide bomber appeared to detonate his explosive device prematurely in the south-eastern province of Paktika. Afghan officials said the man had arrived from across the border in Pakistan along with a group of suspected insurgents.

Taliban fighters have stepped up attacks in recent weeks following a series of operations by Nato forces designed to prevent insurgents from gathering forces for a spring offensive.

Western commanders say that their tactics are working as the spring offensive promised by Taliban leaders has not yet materialised. But local Afghans in the south of the country say large numbers of men and weapons have crossed the border in recent weeks undetected by Nato forces.

© 2007 Independent News and Media Limited