According to details provided by an official, the explosion took place near the Shuhada Chowk, which is on Gulistan Road opposite the police chief's office , 10 injured , of them four critical, have been shifted to Civil Hospital, Quetta .
The official said the incident happened in the area falls under a high security zone, with offices of senior police officials and Police Lines, Security forces have cordoned off the site while rescue services are tending to those injured in the incident.
Two vehicles were damaged in the incident, footage of the incident showed.
A police spokesperson said, the bomb disposal squad has been called to the site and investigations are under way.
The nature of the blast has not been ascertained yet.