|Map showing the location of Hangu District (highlighted in red) within the North-West Frontier Province (NWFP) of Pakistan. (Photo credit: Wikipedia)|
Forty-eight people were wounded in the attack in a narrow lane in the town of Hangu that houses both a Shi'ite and a Sunni Muslim mosque.
Officials said the anti-Taliban Sunni Supreme Council often holds its meetings in the Sunni mosque, which made it a possible target.
But district police chief Muhammad Saeed said that the attack was aimed at Shi'ites and that Sunni Muslims were unintended victims.
"Most of the dead were moving in and out of the mosques in the marketplace after Friday prayers when the bomb went off," senior police officer Imtiaz Shah said.
Hangu, part of Pakistan's border region with Afghanistan, has been racked by sectarian violence between Sunni and Shi'ite tribes whose mosques, homes and shops are often close to one another.
Hangu 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.
No group had claimed responsibility for the attack by late evening.
By Saud Mehsud and Faris Ali
HANGU, Pakistan | Fri Feb 1, 2013 1:58pm GMT
(Writing by Mehreen Zahra-Malik; Editing by Nick Macfie)