The police said the explosive device had been planted inside the Rahmania Mosque in Pashtoonabad and went off as worshippers gathered for Friday prayers. Prayer leader Hafiz Ataur Rehman was among the dead and over 25 were injured in the blast, Geo News reported on Saturday.
The Counter-Terrorism Department on Saturday registered a case against unknown persons. No group has claimed responsibility for the attack.
According to Pashtoonabad Police Station SHO Tauseef Farman, an explosive device was planted in the chair of the prayer leader that exploded before the prayers began.
Pakistani Prime Minister Imran Khan and President Arif Alvi condemned the explosion.
A police official said that up to two to three kg of explosive material was used in the attack.