At least 19 people were killed when a suicide bomber blew himself up at a mosque in an army cantonment area in northwestern Pakistan on Thursday night, the third such attack in the country in a day.

The attack took place during evening prayers in Kohat in North Western Frontier Province, some 70 kms from Peshawar.

Interior Minister Aftab Khan Sherpao told the media that 14 people, most of whom were army recruits, were killed when the bomber blew himself up in the midst of the prayer congregation.

Local reports said 19 people, including two children, were among those killed.

Sherpao said the blast was the fallout of the military raid on the Lal Masjid in Islamabad on July 11.

The mosque is located in army lines and no civilian can enter that areas, local reports said.

The bomb shocked the military establishment as it took place in the high-security area despite a red alert all over the country.