Builder mafia is active in constructing illegal structures in connivance with the Sindh Building Control Authority (SBCA) in the metropolis, alleged MPA Bilal Ghaffar here on Monday. He said despite several complaints filed against illegal constructions in Mahmoodabad Dadabhai Town, no action had been taken against the mafia, according to a communique. Expressing his reservations over the ongoing illegal construction in Karachi, he alleged that the provincial governmentwas promoting illegal structures in the city.