A suicide bomber killed 19 mostly Sunni Muslims and wounded 45 on Friday in a crowded market outside a mosque in Pakistan's restive northwestern town of Hangu, police and officials said.
Hangu, part of Pakistan's border region with Afghanistan, has been racked by sectarian violence between Sunni and Shi'ite tribes.
It is just a few km from Parachinar, which has a significant Shi'ite population against whom hardline Sunni militant groups have launched attacks for years.
"Most of the dead were coming out of a mosque in the marketplace after Friday prayers when the bomb went off," senior police officer Imtiaz Shah said.
No group has claimed responsibility so far.