Intelligence agencies have sounded a terror alert in Kolkata, Mumbai, Delhi and major cities in Gujarat following reports that terrorists had sneaked into these cities to target vital installations.
A top Union Home Ministry official today said that Taliban-trained 'fidayeen' (suicide squads) have entered the country to carry out attacks at specific installations.
In Mumbai, the security arrangements at the Bhabha Atomic Research Centre and the Bombay Stock Exchange have been beefed up.
The headquarters of the Rashtriya Swayamsevak Sangh is also among the likely targets of the 'Pashtoon-looking' terrorists, the official said, adding that instructions have been issued to tighten the security net around these installations.
Police forces in all four states have been put on high alert and efforts are on to nab the terrorists at the earliest.