A horrific fire that tore through a Karachi garment factory killing more than 250 trapped workers was started by politically-connected extortioners, a long-awaited investigation has concluded. The blaze at the Ali Enterprises factory in the Baldia town area of Karachi in 2012 was set after the owners refused to pay a bribe to representatives of the Muttahida Qaumi Movement (MQM) party, according to the findings published on Monday. The 25-page report sharply criticised the original police investigation for being swayed by the influential culprits into blaming the factory owners. Officers at first said the blaze in a factory packed with rolls of denim and cotton cloth had probably been caused by an electrical short circuit and the owners were at fault. But the Sindh provincial government ordered a second inquiry, which began in 2015. The joint investigation team of nine senior police and intelligence officials concluded instead that the fire was “a planned sabotage/terrorist activity and not an accidental fire, carried out due to refusal to pay extortion of 200 million rupees”. The fire in September 2012 is one of the country's worst industrial tragedies. Witnesses described horrific scenes of workers stampeding to get out as the flames took hold, only to find they were trapped. Those unable to escape frantically called relatives for help until they were overcome by the blaze. A total of 259 people died in the fire and about 50 were injured. Investigators were told that local MQM officials frequently extorted money from the factory under the pretext of religious collections, or party donations. Several weeks before the blaze party officials had demanded a bribe of 250m rupees (Dh5.5m), warning that otherwise the party would take a share in the business. The owners refused and attempted to reach a settlement, but the party refused to drop their demand below 200m rupees. A witness told investigators he had seen a factory worker who was a known MQM activist meet several strangers on the premises minutes before the blaze erupted. The group were seen throwing plastic shopping bags containing unknown material around the factory warehouse seconds before the fire erupted, then they all ran out. The factory accountant told investigators that the blaze was so intense that it quickly “engulfed the entire warehouse and flames were bulging out of the warehouse as if dancing in the air”. The report on Monday said the initial police investigation appeared to have been hopelessly compromised. “The incident was handled from inception till end in a way and fashion to benefit the offenders rather than the victims of crime for some motives and gains,” the investigators said. The report went on to say the police had been dominated by “fear and favour” throughout. Several of the accused had since fled abroad and should be extradited as soon as possible, the report said. The MQM was founded in 1984 as the party of Urdu speakers who migrated from India at the time of Partition and has held considerable sway in Karachi. The party has long been accused of using violence to maintain its political influence.