Herat Police spokesman Abdul Ahad Walizada has confirmed an explosion ripped through Nabi Akram Mosque in PD7 in Herat city, Tolo News reports.
Walizada said at least one person was killed and seven wounded in the explosion but said the casualty toll could rise.
He said victims had been taken to local hospitals.
According to him the explosion tore through the mosque during mid-day prayers, shortly after 1pm.
No details have been released on the type of explosion but Walizada said police are investigating.