KARACHI - The Tehreek-e-Taliban Pakistan (TTP) has demanded Rs220 million extortion from Pakistan State Oil (PSO) and warned to halt oil supply to the Nato forces engaged in war against terror in Afghanistan. According detail, unanimous caller phoned the PSO administration up, demanding Rs220 million extortion and warned to suspend the oil supply to the Nato forcers. Source privy to the matter disclosed that threatening calls and warning had been continued for last couple of months and the PSO administration had taken all possible security measures to avert any possible attack. The source further said that the National Crisis Management Cell had already issue warning of the possible attacks at PSO installations. He claimed that recently a caller, stationed in Waziristan, called the PSO administration and demanded the extortion amount. The caller also warned suspend the oil supply to the Nato, he added. He said that the PSO administration had taken the warning serious and had taken all precautionary measures to avert any attack like the one at PSO Tarojabba Oil Depot when militants fired three rockets. Ferrier Police SHO Ishaq Lashri confirmed the threats and said that PSO General Manager Security and Aviation Shahzad Manzoor had submitted an application to the police. The SHO further said that the police had made all possible security arrangements at the PSO Tower located in Clifton area after the threatening call. He claimed that during the initial course of investigation the location of the caller had been traced to be in the volatile Waziristan. Sources in the PSO said that following the threats and warning, the administration had removed the parking facility from outside the office and had erected steel and cemented barricades at all entry and exit points. They said that the administration had been revisiting the strategy for the oil supply to the NATO forces which usually been go through the Terminal C located in Kemari and Zulfiqarabad.