Swat valley had been one of the country's main tourist destinations until last year when Pakistani Taliban fighters infiltrated from enclaves on the Afghan border.

Violence had briefly subsided in the region when a coalition government came to power after elections in February and opened talks with fighters.

Authorities in the North West Frontier Province reached a peace deal with fighters in the Swat valley in May, but attacks intensified again across the northwest, including the Swat valley, after Baitullah Mehsud, the Pakistani Taliban leader, suspended talks in June.