In a second major suicide bombing in the Pakistani capital within a span of a month, atleast eight persons were feared killed and seven others injured when a vehicle laden with explosives was rammed into a complex in the Police Lines housing the office of the Anti-Terrorism Squad.
The suicide bomber drove his vehicle into the three-storey office office around one pm and seconds later the whole area became an inferno of smoke and fire.
The blast came even as a high security alert was in place as just 20 kms away, lawmakers were discussing in a joint session the strategy to be adopted to combat an upsurge in the terrorist violence in the country.
Some reports put the death toll at eight while Dawn News channel reported that four persons were killed. Police officials said casualties were limited by the fact that most ATS personnel had been deployed for security duty at the Parliament house.
The impact of the blast was so huge that one side of the ATS building collapsed completely and the houses and buildings several kilometres away had their windows shattered. The blast also also scorched trees and destroyed about 20 cars and motorcycles.
Policemen cordoned off the area as investigators scoured the site of the blast for clues and body parts of the suicide bomber. Several injured persons were rushed to nearby hospitals by ambulances.
The Islamabad Police headquarters and the National Police Academy are located within the Police Lines. The area also houses the International Islamic University, a government hospital and one of the city's largest fruit and vegetable markets.
President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani condemned the attack, vowing that the government would would not be deterred in fighting terrorism.
The facade of the building housing the ATS office was destroyed and a staircase collapsed.
A police official said the ATS building was located deep inside the police complex.
According to official data made public recently suicide attacks have killed more than 1,200 people in Pakistan since July last year, most of the civilian.