It was the first suicide attack in Swat since July, when the government said a military offensive against the Pakistani Taliban in the valley and surrounding areas had largely been successful.
Several soldiers manning the checkpoint were wounded in the attack in the town of Khawaza Khela, said senior police official Idrees Khan. He gave no further details and said officers were investigating.
The military has been winding down its three-month offensive in Swat, although the army said it still faces pockets of Taliban resistance in the surrounding area. Hundreds of thousands of the roughly 2 million people who fled the area during the fighting have been returning home amid tight security.
Pakistan has said troops will remain in Swat until the fighters of notorious Taliban leader Maulana Fazlullah
- whose thousands of followers are blamed for the violence - are eliminated. Although the military says it has killed or captured a number of Fazlullah's commanders, he himself has evaded capture.
Meanwhile, a Pakistani army officer and two intelligence officials said Saturday that a clash between Pakistani and Afghan border guards killed a Pakistani soldier and wounded 12 others.
The officials, who spoke on condition of anonymity because they were not authorized to speak to the press, said the clash took place near the border town of Angore Adda in the South Waziristan tribal region after mortars fired from Afghanistan struck a Pakistani post Friday. They said Pakistani forces returned fire, and the shootout continued for two hours.
But Afghanistan's border police command said there was no clash, although there had been an operation carried out 12 miles (20 kilometers) inside Afghanistan in Khost province that borders Waziristan.
Skirmishes between Pakistani and Afghan forces along the border have occurred in the past, although none have been reported in recent months.
