Also on Saturday, four Taliban fighters were killed in the southeastern province of Paktia, a defence ministry statement said Sunday.

Taliban militants, who ruled Afghanistan for more than five years before they were toppled by a US-led military invasion, are most active in southern and eastern regions. The militants seem to have also recently expanded their activity to western and northern provinces.

A London-based think tank said Friday that Taliban militants have permanent presence in 80 percent of Afghanistan, while they conduct 'substantial' activities in another 17 percent of the country.

More than 100,000 international soldiers, two-thirds of them US troops, are currently stationed in Afghanistan.

Following the deployment of more than 20,000 extra troops this year, the US government is expected to send additional forces to Afghanistan in the hope of reversing recent gains made by Taliban.