At least four people were injured in a blast outside a mosque on Quetta's Sariab Road on Friday, police said.
The wounded were shifted to the Civil Hospital for treatment. The incident took place after Friday prayers.
A video showed worshippers coming out of the mosque as an explosion was heard and plumes of smoke rose from a motorcycle on fire.
Quetta Deputy Inspector General Abdul Razzaq Cheema said that the nature of the explosion cannot yet be determined and police are investigating if explosives were planted on a bike or if the vehicle caught fire.
Police cordoned off the area as the probe into the blast went underway.
According to state-run APP news agency, shops were shut down as panic gripped the area following the blast. Rescue services were also dispatched to the site.
