Earlier on Friday, US special forces launched an attack on the suspected Taliban targets in Gor Tata, a town on the outskirts of Kunduz City.

Afghan officials said 11 Taliban fighters were killed in the attack, but witnesses said only five had died and the the group itself totally denied that any raid had taken place.

Increasing attacks

The once relatively calm province of Kunduz has seen a significant increase in Taliban activity recently.

Earlier this month, two journalists were kidnapped in the province, where they had travelled to visit the scene of a Nato air raid.

Stephen Farrell, a British-Irish reporter for the New York Times, was rescued during a British military operation to free the journalists last week.

His colleague, Sultan Munadi, an Afghan journalist, was killed in the raid on a house in Kunduz where the two journalists were being held.

A Taliban commander who was in the house was killed, along with the owner of the house and a woman who was inside, Mohammad Sami Yowar, a spokesman for the Kunduz governor, said.

The two journalists were in Kunduz to investigate the Nato air attack that is believed to have scores of civilians.