Kolkata, Mumbai and Gujarat and Delhi have been put on high alert following intelligence inputs that Taliban-trained terrorists have sneaked into these cities to target vital installations. <br/><br/>A top Union Home Ministry official on Monday said that Taliban-trained suicide squad have entered the country to carry out attacks at specific installations, including Bhaba Atomic Research Centre, defence establishments Bombay Stock Exchange and RSS headquarters among other likely targets.<br/><br/>Instructions have been issued to lay a tightened security net around these installations. He said the police forces have been put on high alert following the inputs and efforts are on to nab the terrorists at the earliest<br/><br/>Maharashtra put on high alert and security beefed up at vulnerable installations such as the Bombay Stock Exchange, airports, ports, Bhabha Atomic Research Centre (BARC).<br/><br/>The terrorists, who have entered the metro, are described as Pashtuns, who are well-versed in terror tactics and low-intensity warfare.<br/><br/>The police agencies in the state have been told to look out for men with distinct features identified with Pashtuns such as a well-built physique, good height, sharp features and fair skin.<br/><br/>In Gujarat, a high alert has been sounded following threat of suicide attack by the terrorist group trained by Taliban.<br/><br/>AIR Ahmedabad Correspondent reports that all Police Commissioners and Superintendent of police have been asked to remain alert following the threat.<br/><br/>Security has been tightening on all sensitive places including historic Somnath Temple on the coast of Arabian Sea. Police have been asked to remain vigil in Ahmedabad and other sensitive places of the state.<br/><br/>Strict vigil also maintained at all religious places, bus stations, railway stations, airports and crowded markets. Vehicles entering the state and district borders are being checked; similarly strict vigil also kept on Hotels and Restaurants.<br/><br/>