At least 20 people were killed when a suicide bomber blew up himself in a mosque in northwestern Mohmand Agency tribal area, local media reported Friday. 

Dozens more were injured when the bomber detonated his explosive-laden vest during Friday prayers, according to local Dawn TV.

Death toll may shoot up as several injured are stated to be in critical condition.  

Bordering Afghanistan, Mohmand Agency is one of the seven semi-autonomous tribal areas of Pakistan, and considered one of the nerve centers of the Pakistani Taliban.