KARACHI, May 25: One labourer was killed and three others were injured when a parcel bomb exploded on the premises of the Karachi Port Trust on Monday evening. The parcel, placed on a pavement, exploded with a bang, leaving the four men injured. They were taken to Civil Hospital by Edhi ambulances where one of them died.

Hospital officials identified the deceased as Fateh Mohammed and the other victims as Tariq, Nasrullah and Jamil Ahmed. Tariq's condition was serious and he was in the operation theatre till late night.

"It was not a suicide attack. There is a small crater on the concrete pavement which suggests that something was placed on it," DIG operations Tariq Jamil told Dawn. He said police had nothing to do with security within the KPT premises as it was the responsibility of the KPT itself. He said the incident would be investigated to ascertain facts.

Nasrullah told doctors that they had parked their container-carrying truck and were waiting for their turn to unload the container at a berth. He said the labourers were standing beside a security post near Gate No 17.

"We saw a suspicious-looking parcel lying on the pavement. While I was still thinking to inform the security personnel about the parcel, it exploded with a bang," doctors quoted Nasrullah as saying.

Rangers and police officials inspected the spot and the area was cordoned off. On May 7, a suicide bomber had blew himself inside the Hyderi Mosque, killing 14 worshippers.

The death-toll has since increased to 22. Seven suspected members of the banned Harkatul Mujahideen Al-Alami, including its leader Kamran alias Atif, were arrested. "I don't think that today's blast is a reaction to these arrests," said the DIG in reply to a question.