The suicide bomber detonated his explosives in a crowded area of Quetta's Hazara town where people were shopping for Eid, said Abdul Razaq Cheema, a capital city police officer, Dawn reported.
The ethnic Hazara Shia community of Hazara town is believed to be the target of the extremist militant groups.
All the injured were rushed to the Bolan Medical Complex Hospital and Combined Military Hospital (CMH) and an emergency was imposed in all government-run hospitals soon after the blast, a provincial government spokesperson was quoted as saying.
The blast was followed by aerial firing in the area and shopkeepers pulled down their shutters in panic.
A huge contingent of police and Frontier Corps (FC) personnel reached the spot to cordon off the area.
The explosion was the second bomb attack in the city in the past 24 hours.
Earlier in the day, seven people were injured when an IED (Improvised Explosive Device) exploded in Quetta's Spini road area. Police said militants targeted the vehicle of a deputy superintendent of police in the attack.
No militant group has so far claimed responsibility for the suicide bombing.