Karachi police said they defused a bomb left in a makeshift mosque inside a hospital compound, fearing it could have detonated during Friday prayers.
The police found a bag in a tented mosque in the residential colony of Jinnah Postgraduate Medical Centre with the live bomb inside.
“Some witnesses informed the police about a suspicious looking bag, which some unknown men had abandoned in the mosque,” Iqbal Mehmood, a senior police official, told reporters.
Another police official said on condition of anonymity that it was a remote-controlled bomb and that police feared it could have been detonated during the Friday prayer in the afternoon.
Mehmood said the home-made explosive device weighed at least 15 kilogrammes (33 pounds).
Karachi suffers from killings linked to political and ethnic tensions and crime, but Islamist militant violence is also on the rise in the city of 16 million people whose port is a hub for NATO supplies bound for Afghanistan.
Last month, it took the navy 17 hours to fight off a handful of militants who killed 10 security officials and destroyed two US-made aircraft at the only naval air base in Karachi.
