Hours later, gunmen opened fire at a passenger train, killing four persons and injuring three others, police said.

President Pervez Musharraf condemned the attacks, saying such “acts of terrorism cannot deter the government’s resolve to fight the scourge with full force”. He said those behind the attacks would be brought to justice.

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.

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.

Walls, stairs and columns collapsed as several of the lower floors were reduced to rubble. The terrorist strike 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, 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.

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.

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 into the city from Faisalabad. The assailants fled after the attack

Australia scraps tour, Musharraf agrees to call Parliament on Monday

• Australia on Tuesday scrapped its cricket tour of Pakistan, barely a few hours after the twin blasts rocked Lahore. “This was a difficult decision based on independent review of the circumstances prevailing in Pakistan,” CA chairman Creagh O’Connor said

• Setting the stage for a showdown with the Opposition, Musharraf summoned the first meeting of the new Parliament on March 17. This comes after PPP and PML-N agreed on a coalition government