At least 12 people have been killed and dozens injured after a car bomb exploded at a market in north-west Pakistan, officials say.
The blast hit the town of Parachinar in the tribal area of Kurram.
Last year, Pakistan's army launched an offensive against militant groups in Kurram. The area also has a history of violence between Sunni and Shia groups.
In February, a suicide bomb attack close to a mosque in Parachinar left 26 people dead.
Officials told the Reuters news agency that the death toll from Monday's blast was likely to rise because many people had been walking along a narrow road adjacent to the market. At least 30 people were injured.
"The car detonated as a security convoy passed by in the Turi Market," police official Sahibzada Mohammad Anis told the AFP news agency.
The injured have been taken to a district army hospital and police have cordoned off the area of the blast, local media report.
About 30 shops were destroyed and 50 damaged in the busy commercial area, police say, leaving the site littered with rubble and twisted metal.
Officials say that it is not clear whether it was a suicide attack. Nor is it clear whether the target was a security forces' convoy or members of Pakistan's minority Shia community.
No group has said it carried out this attack, but the Taliban and other Sunni militant groups are known to be active in the area.