Meanwhile, Afghan and foreign troops in the eastern Paktika province killed seven suspected fighters in clashes close to the Afghan-Pakistan border, a spokesman for the provincial governor said.

The fighters entered Afghanistan from Pakistan and launched an attack on Afghan border guards in Bermal district, Ghamai Mohammadyar said.

There were no casualties among Afghan and foreign troops, he said.

The Taliban frequently targets the police and army in Afghanistan. More than 1,000 police officers died in attacks blamed on the Taliban last year.

Afghan and Western officials say Taliban and other fighters often use Pakistan's tribal areas as bases for launching attacks against Afghan and foreign troops in the country.