A dual bomb blasts in the Pakistani city of Karachi, have killed at least 40 people.

Report has it that the bombers targeting Shia Muslims marking a religious ceremony,

A bomb-laden motorcycle first exploded on a main road in the city as a bus carrying Shia worshippers passed on Friday.

The second blast went off outside the hospital where the wounded were being taken.

"An explosion occurred at the Jinnah hospital near the emergency ward, where the bodies and injured were being taken," Dr Mushtaq Ahmad said.

"I heard a large blast. People are running all over the place."

Police later said they had defused a third explosive device in the premises of the hospital.

"The bomb was planted in a television set and we successfully defused it," Ghulam Nabi Memon, a senior police officer, said.