The issue of civilian casualties is hugely controversial
At least 18 civilians have been killed in an air strike by foreign forces in the southern Afghan province of Helmand, reports say.
A BBC reporter in the provincial capital Lashkar Gah saw the bodies - three women and the rest children - ranging in age from six months to 15.
The families brought the bodies from their village in the Nad Ali district, where they say the air strike occurred.
A further nine bodies are said to be trapped under destroyed buildings.
Nato-led forces say they are investigating the incident in an area where the British military are known to operate.
The BBC's Martin Patience in Kabul says that civilian casualties are hugely damaging to foreign forces trying to wage a "hearts and minds" campaign.
On Sunday, Afghan and UK officials said that dozens of Taleban insurgents died in a battle with Afghan and Nato-led forces on the outskirts of Lashkar Gah.
Three days later they said that a further 18 militants were killed while attacking a police checkpoint in the same area.
Figures released in September by the United Nations said there had been a sharp increase in the number of civilian casualties in Afghanistan in 2008.
US air strikes have been blamed for many civilian deaths
They showed that August had the highest number of deaths since the overthrow of the Taleban almost seven years ago.
The UN said that from January to August 1,445 civilians were killed - a rise of 39% on the same period last year.
Earlier this month the US military said that air strikes on 22 August killed 33 Afghan civilians, many more than previously acknowledged.
And in what correspondents say is another notorious incident, an Afghan parliamentary investigation in July found that a US airstrike in the same month killed 47 civilians in the eastern province of Nangarhar.
Regional officials said the casualties were attending a wedding party and that the bride had been killed.
In a separate incident on Thursday, an Afghan policeman shot dead a US soldier in the eastern province of Paktika. It is the second time that this has happened in recent weeks.
In an interview with the Reuters news agency, the the US general in command of Nato and American forces in Afghanistan, David McKiernan, said that the increase in violence over the last year was due to the resurgent Taleban being forced to shift tactics.
He said they were now carrying out "small scale, asymmetric, more complex attacks," on soft targets like civilians, aid workers and government officials.