At least 15 people have been killed by a bomb blast in a crowded market in a town in northwest Pakistan's Kurram tribal agency, near the Afghan border.

More than 40 people were hurt in the blast at the Eid Gah clothes market in the town of Parachinar.

TV images showed people fleeing over ground covered in clothes and debris.

No group has said it carried out the attack but a sectarian motive is suspected, as most people in Parachinar are from Pakistan's Shia minority.

Kurram has a history of sectarian violence between Shia and Sunni Muslims, and agreements to calm tensions between the communities have not been implemented.

Several Taliban-affiliated groups are known to be active in the region.

Violence in the country overall has fallen since the Pakistani army embarked on an offensive against the Taliban and other militants in the North Waziristan agency, bordering Kurram.