At least six people were killed in the second blast including DSP Kamal Khan and three other police officials while ten people sustained injuries.
The injured were shifted to Jinnah Hospital.
The second bomb was remote controlled that was placed in a cement block in which ball bearings were used.
Bomb Disposal Squad was called in to determine the intensity of the explosion
At least six people were killed in twin blasts near Muzaffar Colony in Landhi area on Thursday.