KARACHI: Police said they defused a bomb left in a makeshift mosque inside a hospital compound in the country's biggest city of Karachi, 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.

Speaking to media representatives, the official said that more than 20 kilograms of explosive material, including two detonators, was hidden inside a sack and was planted at the location.

He added the explosive device was similar to the ones used in the naval bus attacks earlier this year.

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 main Friday prayers in the afternoon.

Mr Mehmood said security was being tightened around places of worship and the city had been put on high alert. Moreover, search operations were being conducted at mosques and imambargahs across the city.