Thiruvananthapuram:The Kerala police has sought the help of Interpol to nab some foreign nationals suspected to be behind the fraudulent withdrawal of Rs 2.50 lakh from ATMs using duplicate cards. Additional Director General of Police B. Sandhya on Tuesday visited an ATM of the State Bank of India located in the heart of the city. "Scientific evidences is being collected. We have got in touch with other state police and have also sought the help of Interpol," Sandhya told reporters. Some Russian and Kazakh nationals, who were in the state capital for 10 days, are suspected to be involved, according to police. The matter came to light after 50 complaints were registered by city residents of their money being withdrawn fraudulently. All of them used to frequent the SBI ATM at Alathara here. The police, after initial probe, said the gang had fixed an electronic device that looked like a smoke alarm in the ATM kiosk, and an ATM card reader. The police said the electronic device took a picture when the customer keyed in his secret PIN number, while the device placed in the card reader got the information of that particular card. The gang made a duplicate card and withdrew money from ATMs located outside the city. The visuals of two foreign nationals working on the 'smoke alarm' inside a SBI ATM was shown on TV channels on Tuesday. "I was surprised to get an SMS alert on Sunday when I was home that there were two withdrawals of Rs 10,000 each in a space of two minutes. I rushed to the ATM and when I took a statement of my account, I found out that I had lost money. Later I came to know that the withdrawal had taken place in Worli in Mumbai," said an SBI customer. Meanwhile, a special team has been formed under IG of Police, Manoj Abraham, to probe the incident. A group of officials has already left for Mumbai. "The state police chief has informed all bank officials to see that they conduct an immediate inspection of all ATM kiosks to ensure that everything is fine," Abraham told reporters. The police has also advised people to change the PIN of their ATM card to prevent any foul play.