The blast ripped through a busy Shiite market district Saturday injuring at least 169 people, including women and children, the BBC reported.
The Sunni militant group Laskhar-e-Jhangvi has claimed responsibility for the bombing.
Security sources told the BBC Pakistani police have killed the bomb maker and three others in connection with the attack.
Previously, authorities have been accused of turning a blind eye to the killing of members of the Shiite minority by hard-line Sunni militant groups.
The Quetta bombing sparked strikes and protests across Pakistan and relatives of the victims refuse to bury the dead until officials take action to stop the violence.
Quetta is the capital of Balochistan province that borders Iran and Afghanistan.
The province has been plagued by separatist rebellion as well as sectarian violence.