Kolkata: The police are suspecting that a gang comprising some Nigerian nationals was behind the unauthorised withdrawal of money from various bank accounts, after skimming of debit cards to get details.The modus operandi of the crime made the police suspect that there could be a “Nigerian” gang behind the entire operation. Preliminary investigation has revealed that the cash was withdrawn using the debit card details from certain places in Delhi. In most of the previous such cases in which money was withdrawn from Delhi, involvement of a “Nigerian gang” was found. Also Read – Rain batters Kolkata, cripples normal lifeThe police have gone through the video footages of surveillance cameras installed in three ATM counters at Mallick Bazar, Golpark and Elgin Road. In these three counters, skimming machines were found fitted at the slot of the ATM machines, where one needs to swipe cards to withdraw money. The video footages have shown a person entering the ATM counter to fit the skimming machine. He had his face covered.Police suspect that the same person had installed skimming machines in all the three ATM counters. In one of the video footages he was found covering his face with a handkerchief. In another he was wearing a cap and in the third ATM counter, he was seen wearing sunglasses. As a result, the police have not got a clear picture of the person and so are preparing his portrait parle. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedPraveen Tripathi, Joint Commissioner of Police (Crime), said: “We are taking all necessary steps to crack the case as early as possible.”It may be mentioned that till yesterday, the police had received as many as 76 such cases and on Thursday, two more such cases have been recorded. Police suspect that the number of cases could go up.Some bank officials, including an assistant general manager of a nationalised bank, have also fallen victim to it. Around Rs 40,000 was withdrawn from the bank account of the assistant general manager. He was earlier the manager of the Golpark Branch of the bank. In another case, Rs 50,000 was withdrawn from the bank account of RJ Nilanjana. She has lodged a complaint with Alipore police station. The police are also keeping a watch at the online shopping sites to get information if skimming machines are being sold without necessary permissions.