Secretary of Sindh Province Hashim Raza Zaidi confirmed that 33 people were killed and 60 people have been injured in the deadly attack.
Angry mob attacked government buildings, markets, banks and torched vehicles in the Karachi after the deadly suicide attack on the Shia mourning march, police said.
The Shia march was taken out of Nishtar Park and was on way to head to the final destination. The organizers decided to continue procession despite the blast. They appealed to the mourners to be peaceful.
According to police, it is the third bomb blast in Karachi in three days.
More than 500 people have been killed in attacks since mid-Oct 2009 when the army launched a major anti-Taliban offensive in the country's northwest.