The explosion in a remote area bordering Afghanistan came as people gathered for Friday prayers near the women’s entrance of a Shiite mosque in the central bazaar, the latest in a series of attacks across Pakistan this year.
The local political agent, Ikramullah Khan, said the death toll had reached 22, with 70 wounded.
Sajid Hussain, a parliamentarian from Parachinar, said gunfire preceded the blast, which he described as a suicide attack. The city is located in an area with a large Shiite population, Reuters reported.
The terrorist group Tehrik-i-Taliban Pakistan (TTP), often referred to as the Pakistani Taliban, said the blast was part of its operation Ghazi, named after a radical leader killed by Pakistani security forces in 2007.