KARACHI, May 27: Authorities said on Thursday they suspected a network of religious militants, possibly aided by Al Qaeda, were behind a double car bomb attack near a US consul's residence in which a policeman was killed and over 30 people were injured.

Two bombs exploded less than half an hour apart on Wednesday afternoon in front of the Pakistan American Cultural Centre, a private English school, and some 100 metres from the US Consul General's residence. No one has been arrested so far.

"Al Qaeda, maybe, had a role," Information Minister Sheikh Rashid said. Such an organized attack cannot be just by local people. The attackers were real experts and operated in a very technical way."

Police cast suspicion on supporters of Harkatul Mujahideen Alaami, a gang of militants, who unsuccessfully tried to blow up President Pervez Musharraf's motorcade in Karachi in April 2002 and detonated a car bomb outside the US consulate two months later, killing 12 Pakistanis.

"We strongly suspect Alaami," senior police investigator Manzoor Mughal told AFP. Followers may have retaliated for the arrests, days before the attack, of seven members, including suspected key terror operative Kamran Arif, Mr Mughal said.

Police issued sketches of two suspects who had stolen at gunpoint one of the cars from a nearby market less than two hours before the attack. One of the men was bearded and the other had a thin moustache.

"They planted the lethal explosives in the car and parked it" half an hour before the blast, police investigator Fazaaz Laghari said. Security was bolstered on Thursday around the already heavily-guarded US consulate. Authorities declared a "high security area" in the square kilometre surrounding the building.

APP adds: The law and order situation in Sindh was reviewed at a high-level meeting held at the Chief Minister's House with Interior Minister Makhdoom Faisal Saleh Hayat in the chair. The interior minister informed the chief minister that the federal government would extend full cooperation for eradication of terrorism in Sindh.