A bomb went off outside the campus of a university in the Pakistani port city of Karachi on Saturday, killing at least one person and injuring several others.
The blast occurred near a gate of Karachi University at about 11 am. Witnesses told TV news channels that a man riding a motorcycle was seriously injured in the blast.
They said they had collected the man's body parts and he was taken to hospital in a private vehicle.
The injured man subsequently died in hospital, officials were quoted as saying by news channels.
Several others were injured by the blast. Police officials told the media that a preliminary investigation had indicated that the bomb was planted by the roadside.
The blast, which was heard from several kilometres away, damaged several buildings and vehicles. Security forces cordoned off the area after the blast and shops were shut down.
Col Shafiq Niazi, a spokesman for the paramilitary Pakistan Rangers, said a security forces vehicle had been in the area at the time of the blast but it was not clear whether it was the target of the attack. He said the force would increase security across Karachi to prevent more such attacks.
Footage on television showed the mangled remains of a motorcycle lying at the site of the blast.
Pakistan Rangers personnel took up positions on top of buildings as members of the bomb disposal squad scoured the area.
Three Pakistan Rangers personnel were killed and four more injured when their vehicle was targeted with a roadside bomb in Karachi yesterday. That attack had occurred about a kilometre from the site of today’s blast.
Security officials said similar improvised explosive devices had been used in Friday's attack and two other blasts in Karachi on December 4 and 5.