Separately, two soldiers were killed in a roadside bombing and two Islamist militants died in a raid on their bunkers in Swat and Dir districts of the neighbouring North West Frontier Province.

Thousands of Pakistani military and paramilitary troops launched an operation in the districts two months ago to expel the local Taliban, who backed out of a purported deal with the government to implement Islamic law and moved dangerously close to the capital, Islamabad.

After a bloody campaign resulting in the death of more than 1,700 militants and more than 160 soldiers, according to the government, the army last week announced the clearing of a major town, paving the way for the return of more than 1.9 million people displaced by the fighting.

The Taliban have lost strongholds in the northwest but frequently attack the military, which is conducting search operations in the areas captured from the militants in Swat and three neighbouring districts.