The government has warned telecom subscribers against unfamiliar international calls and also asked mobile service providers to tag such calls for awareness of their customers, an official statement said on Tuesday. The Department of Telecom said that within 24 hours of launching 'International Incoming Spoofed Calls Prevention System' on October 22, about 1.35 crore or 90 per cent of all the incoming international calls with tempered Indian phone numbers were identified as spoofed calls and blocked by telecom service providers (TSPs) from reaching Indian telecom subscribers. The fraudsters, thereafter, have shifted their tactics and are using international numbers for their deceptive practices, the official statement said. "The DoT advises citizens that they should show caution with respect to answering calls from unfamiliar international numbers which are not starting with +91 and which claim to be from government authorities of India. Citizens are advised to report such suspected fraud communications at the Chakshu facility on Sanchar Saathi," the statement said. Fraudsters are now increasingly impersonating government authorities by calling from international numbers that do not start with +91 but start with numbers like +8, +85, +65 etc. The DoT has formed a dedicated task force to address issues of spoofed calls and one of the recommendations of the task force was that telecom operators should display 'International Call' to the subscribers whenever any call from outside the country is received. The suggestion was based on the assumption that it would help the users understand that such calls cannot be from Indian authorities or organisations like Trai, Police, Income Tax etc. "One of the TSPs (Airtel) has implemented the technical solution and has already started displaying 'International Call' for all calls received from outside the country. Other TSPs are exploring the technical feasibility of implementing the same," the statement said.