A Pakistani police official says an explosion at a mosque in restive Baluchistan province's capital of Quetta wounded at least seven people.

Abdful Razzak Cheema, deputy inspector of police, says the blast occurred during Friday prayers at the mosque in Pashtoonabad neighborhood.

The source of the explosion was not immediately clear and no group immediately claimed responsibility for setting it off.

Sectarian violence, mostly targeting Pakistan's minority Shiite Muslims, has left hundreds dead in recent years in Baluchistan. However, the Pashtoonabad neighborhood in Quetta is a Sunni majority area and the mosque was attended by Sunni Muslims.

Militant groups belonging to both sects operate in the area. Baluchistan is also plagued by insurgency by secessionist groups seeking more autonomy or independence for the province.