Islamabad, Feb 2 (IANS): At least 22 people were killed and 40 injured Friday when a suicide bomber triggered a massive explosion that tore through worshippers who poured out of a mosque in a crowded market in Pakistan's Khyber Pakhtunkhwa province, said media reports.

The bombing took place when worshippers were leaving the mosque after Friday prayers in Patt Bazar area of Hangu district, Xinhua cited police official Mian Muhammad Saeed as saying.

Rescue workers said 12 people were killed on the spot while 10 succumbed to their injuries undergoing treatment at a hospital.

Hospital sources said over 40 people were wounded, of which six were in serious condition. They have been shifted to the neighbouring Kohat district for intensive care treatment.

There were conflicting report on the number of mosques. Dawn reported that the suicide bomber blew himself up outside two mosques in close proximity.

The attack occurred in a lane housing two mosques - Masjid Faizullah, frequented by members of the Shia sect, and the other, Masjid Purdil, by members of the Sunni sect, said the media report.

It was not clear if the bombing targeted members of a particular sect as the dead included both Sunnis and Shias.

Bomb squad officials said around seven to eight kg of explosives were used in the blast.

Soon after the attack, all exit points of the area were blocked.

No militant group claimed responsibility for the attack.

President Asif Ali Zardari condemned the incident and directed hospital authorities to provide proper medical treatment to the injured.