Aftab Khatri, health secretary of Sindh province, told Xinhua the toll may rise as many of the injured, including a large number of women and children, were in a critical condition.
No group has claimed responsibility for the blasts.
President Asif Ali Zardari and Prime Minister Raja Pervez Ashraf condemned the blasts and directed the hospitals to provide best possible medical treatment to the injured.
A one-day mourning has been announced in the province Monday. The national flag would fly at half-mast on all state-owned buildings across the province.
According to state-run Radio Pakistan, Zardari and Ashraf said such cowardly acts cannot deter Pakistan's determination to eliminate terrorism from the country.
Sindh Chief Minister Syed Qaim Ali Shah announced Rs.1.5 million each for the kin of those who died in the blasts and Rs.1 million for each of the injured.
