A powerful bomb goes off in southern Pakistan, leaving at least four people dead and dozens injured. The incident is the latest in a series of terrorist attacks that have rocked Pakistan's largest city -- Karachi.
The blast occurred outside a mosque as worshipers were leaving after weekly Friday prayers. Police say the attack targeted a convoy of vehicles, including a government car, passing by the mosque. Some of those injured are in serious condition. So far, no group has claimed responsibility for the attack and it's not yet clear who the target was. The explosion took place a day after a bomb targeted a prominent Karachi police officer, killing him and three others.