The Express Tribune quoted spokesperson for Civil Hospital Quetta,Wasim Baig, as saying that 19 injured and four bodies were brought to the hospital.
The police is investigating the nature of the blast.
Meanwhile, Balochistan Chief Minister Nawab Sanaullah Khan Zehri has condemned the incident.
Further details are awaited.
Last week, a senior police officer and three of his family members were shot down in Quetta. (ANI)