According to local sources, the explosion happened in the mosque located in the Police Line area of Peshawar during afternoon prayer.

Police said that a suicide bomber blew himself up at the mosque as worshipers, including many policemen from nearby police offices, were performing afternoon prayer.

No group immediately claimed responsibility for the bombing.  (ILKHA)

https://ilkha.com/english/world/casualties-reported-after-blast-in-mosque-in-peshawar-pakistan-311702