At least nine Pakistani soldiers have been killed in a suspected suicide attack on a security check post in northwest Pakistan, a security official said.

"A suspected pro-Taliban fighter rammed his explosives-laden car into a small roadside check post in Madyan town in the troubled Swat valley," the official, who asked to remain anonymous, said on Monday.

Pakistan's military sources have confirmed to Kamal Hyder, Al Jazeera's correspondent in Islamabad, that explosives were detonated at a security checkpoint in the Swat valley.

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.