KARACHI, March 15: A vehicle laden with explosives attached with a timer and detonators was left by unidentified men in front of the United States consulate here on Monday. Police seized the vehicle and the explosive device was defused.

"No one has claimed responsibility nor has anyone been picked up so far in this regard," the deputy inspector-general, operations, Karachi, Tariq Jamil, told Dawn.

A police spokesman said in a statement that the police picket in front of the US consulate on the Abdullah Haroon Road witnessed a man, clad in shalwar-kameez, parking a Suzuki high-roof in front of the main gate of the consulate. He alighted from the van and quickly got in a Suzuki Alto car, which was closely following him, and sped away.

The spokesman said that police and Rangers deployed for the security of the consulate got suspicious and cordoned off the van and called a bomb disposal squad, which defused the explosive. The vehicle was taken to another place and searched.

It was found that the rear seats of the vehicle had been removed and a fibreglass water tank of 750-litre capacity containing liquid explosives placed there. The tank was fitted with two detonators and a fuse connected to a washing machine timer device.

The spokesman said preliminary analysis showed that the liquid in the tank contained hydrogen peroxide, ammonium nitrate and sulphuric acid. A detonation would have caused a disastrous impact on life and property, he added.

During investigation it was revealed that the registration number of the vehicle (CA-8501) had been replaced with a government number-plate (GA-0313). The vehicle had been snatched at gunpoint from one Muneeb Tariq in the Baloch Colony area on Sunday evening. Mr Tariq was shot and wounded when he resisted.

Mr Jamil said the film recorded by cameras installed at the consulate was shown to investigators but the faces of the suspects were not recognizable. Civil Lines ASP Omar Shahid said sketches of the suspect had been prepared with the help of a security official.

"It is for the first time that liquefied explosive has been seized. The technique to make the explosive was improvized but it is too early to identify the group behind the incident," Mr Jamil said.

He said the tank was full of the explosive and samples had been sent to a laboratory to ascertain its composition. The report was expected by Tuesday, he said. A Rangers spokesman said there were about 600 litres of the explosive in the tank.