PESHAWAR, Pakistan - Ten people were killed and 14 wounded Sunday in a bomb blast at a polling station in an area of northwest Pakistan rocked by a violent campaign to impose Islamic law, police said.

The remote-controlled bomb went off at a school in the town of Bunir on the edge of the Swat valley, where voters were casting ballots in a parliamentary by-election, local police official Liaqat Khan told AFP.

Eight of the 14 people hurt were taken to hospital in critical condition, another police official, Behramand Khan, said, adding the death toll could rise.

The mountainous Swat valley - once known as the "Switzerland of Pakistan" - was until last year a popular destination for local and foreign tourists that boasted the country's only ski resort.

But the region has been turned into a battleground since radical cleric Maulana Fazlullah, who has links to Pakistan's Taliban movement, launched a violent campaign for the introduction of Islamic Sharia law in the valley.

Pakistani troops launched a major offensive in the area last year, but have since scaled back their operations.