The blast was the latest in a wave of attacks, most in the northwest of the country near the border with Afghanistan, blamed on pro-Taliban militants based in tribal areas on the Afghan border.
Military spokesman Major-General Waheed Arshad said 11 civilians and four policemen had been killed in the suicide blast in the town, which is in North West Frontier Province.
An Interior Ministry spokesman said 11 people -- four of them policemen -- had been killed.
"A burqa-clad bomber -- either it was a woman or a man in a burqa -- set off explosives when police approached," said ministry spokesman Javed Iqbal Cheema.
A police official said the blast went off near a bus stand and 19 people were also wounded.

Copyright Reuters, 2007