By Alastair Leithead
BBC News, Kabul
A boy from Shindand receives treatment for his injuries
There are conflicting reports of civilian casualties in a US-led military operation in west Afghanistan.
Nato forces say two Taleban commanders were killed in Herat province. One of them is a leading tribal elder.
Local tribal elders claim dozens of people, including civilians, also died in the American attack.
Earlier, US forces admitted killing eight civilians in a neighbouring province - the latest in a series of bombing incidents involving civilians.
The first reports of the operation in Herat province came from tribal elders who claimed huge numbers of people had been killed or injured in a US-led attack from midnight until mid-morning in Shindand district.
They said a high-profile tribal leader had died and houses had been destroyed.
There were also unconfirmed reports of demonstrations in the Zerkoh valley, a fiercely independent tribal area where US forces have clashed with local fighters before.
But Nato put out a statement saying that the coalition and Afghan security forces had conducted a successful operation against high priority Taleban targets.
They confirmed a significant number of insurgents had been killed, including Haji Nasrullah Khan, who they described as a Taleban leader.
He is an important tribal elder and last year when US forces were accused of killing civilians in the same area, President Karzai sat alongside him at a shura, or public meeting, and passed on his condolences for those killed or injured.
A spokesman for the Nato-led International Security Assistance Force (Isaf) said they had no evidence of civilian casualties or accidental damage and added that more than a dozen men were found handcuffed and imprisoned in appalling conditions in one of the compounds.
There have been reports in Shindand of smuggling and links between the tribes and the Taleban but Haji Nasrullah Khan was well connected and his death could see President Karzai coming under pressure from tribal allies to whom he was linked.
The different accounts and the complexities of Afghan tribal structures show how confusing the line is between those considered insurgents or Taleban and powerful local leaders, particularly when it comes to the issue of reconciliation and trying to encourage those opposed to the government to switch sides.
Earlier, US forces said they had killed eight civilians in neighbouring Farah province after they were attacked from a number of houses in Bakwa district.
Anger is growing over civilian casualties in Afghanistan
Their statement said a routine patrol came under sustained attack from machine-gun fire on Tuesday from houses adjacent to the road.
"The coalition returned fire and called for close air support on the enemy positions," the statement said.
"A house was hit - eight civilians were killed, two others injured. Coalition forces never intentionally target non-combatants, and deeply regret any occurrence such as this where civilians are killed and injured as a result of insurgent activity and actions."
The issue of civilian casualties has again come up as there have been a number of incidents over the last couple of weeks.
On Thursday President Hamid Karzai visited families of those killed in the eastern province of Nangarhar who had reported that more than 50 people from a wedding party died after being bombed by American aircraft.
President Karzai offered them his condolences and some financial assistance.