Islamabad , Pakistan ( CNN ) -- At least 42 people died and another 145 were wounded in a massive car bombing Sunday in the large Pakistani seaport city of Karachi , authorities said . The toll could rise as rescue workers continued to recover bodies early Monday , said Syed Hashim Raza Zaidi , the top government official in Karachi . The blast apparently targeted Shiite Muslims who lived in buildings surrounding where the vehicle , loaded with 150 kilograms of explosives , was parked , according to senior Karachi police official Rao Anwar Ahmed . A timing device triggered the explosion next to a market in Karachi 's Abbas town , Ahmed said . Two explosions were initially reported , but the second blast has been attributed to a pipe that exploded as a result of the bombing , he added . As of about midnight Sunday , no militant groups were known to have claimed responsibility , said Zaidi . Pakistan 's Prime Minister Raja Pervez Ashraf and President Asif Ali Zardari both immediately condemned the attack . `` Expressing sympathies with the bereaved families , the president directed the authorities concerned to ensure that the best medical treatment was provided to the injured , '' a statement from Zardari said . Pakistani has seen several such deadly attacks in recent years , including one last month that struck a crowded marketplace on the outskirts of Quetta that killed at least 89 people and wounded at least 180 others . That blast followed a January day of bomb attacks targeting Shiites in Quetta that left at least 85 people dead . On February 1 , a suicide bomber detonated his explosives near a marketplace in the northern Pakistan city of Hangu near the Afghanistan border , killing at least 23 people . Such violence is a common problem in the volatile Khyber Pakhtunkhwa province , which , like Quetta 's home province of Balochistan , borders Afghanistan . Karachi , meanwhile , is some 1,350 kilometers ( 840 miles ) south of Hangu and 800 kilometers ( about 500 miles ) from Quetta on Pakistan 's southern coast . Situated along the Arabian Sea , it is the South Asian country 's financial center and its most populated city . Still , despite its distance from Pakistan 's tumultuous western border areas , Karachi has not been entirely immune to violence . In February 2010 , for instance , at least 18 people died in blasts targeting a bus full of Shiite religious observers and another in front of a hospital . And in late 2009 , a suicide bombing targeting a Shiite procession moving through Karachi killed at least 40 people . Get the latest news from CNN.com .
NEW : Rescue workers continue to discover bodies , a Karachi official says . The blast apparently targeted Shiites in Karachi , police say . A timing device triggered the 150 kilograms of explosives , police say . Police say the death toll could rise as more bodies are found in rubble .