At least 28 people were killed and 170 injured in two devastating suicide car bombings that destroyed the federal headquarters of Pakistan's premier probe agency and a house near PPP leader Asif Ali Zardari's residence on Tuesday.
Hours later, unidentified gunmen opened fire at a passenger train here, killing four persons and injuring three others, police said.
The blast that ripped through the seven-storey office of the Federal Investigation Agency located on Temple Road at 9.23 am killed at least 24 people and injured scores.
The explosion destroyed the entire front of the building. Walls, stairs and columns collapsed as several of the lower floors were reduced to rubble. The terrorist strike in the capital of eastern Punjab province comes a week after the attack on a naval college in the city.
Officials said the attack was carried out by a suicide bomber who drove a van packed with over 60 kg of explosives through the gate and rammed into the wall of the FIA office before blowing himself up. The attacker's severed head was found by police and sent for DNA tests.
The blast triggered fires in the FIA office and CNG tanks of cars in the parking lot. At least 12 cars were destroyed and several of them exploded due to intensity of the flames.
The blast, which created a five-foot deep crater, also damaged several nearby buildings, including the office of the Pakistan Olympic Association and a school run by a Christian organisation. Many students of the school were injured by shards of glass from shattered windows.
In the second blast that occurred almost simultaneously in the posh Model Town residential area, two suicide bombers drove a pick-up truck into the compound of a house that had been rented by an advertising agency and blew themselves up.
Reports said the suicide bombers might have mistakenly hit the house as their real target could have been the nearby residence of an Army officer or Bilawal House, the residence of PPP co-chairman Asif Ali Zardari.
Besides the bombers, the blast killed two children of the gardener who worked at the house, parts of which were reduced to rubble. Two persons, including the gardener, were seriously injured in the blast, said police officer Azmat Gondal.
The blast created a seven-foot crater and smashed the windows of all houses within a radius of 100 metres.
The attack on the FIA office created panic in the nearby Mall Road area, a bustling commercial area where shops and commercial complexes were opening for the day when the blast rocked the area.
Over 100 FIA employees had already reported for work when the blast occurred. FIA Director General Tariq Parvez said 16 employees of the organisation were killed.
The city administration declared the FIA office as unsafe and ordered everyone except rescue workers to leave the structure. Officials said they had recovered the close circuit cameras and video recorders fitted to the front of the building and these would be analysed to see whether they had captured the suicide attack.
Several hours after the twin car bombings, four persons were killed and three others injured by unidentified gunmen who sprayed bullets at a coach of the Badar Express that was coming to the city from Faisalabad.
The assailants fled after the attack.
No one has claimed responsibility of the attack. The motive behind the attack was not clear, the police said.