New Delhi, Dec 14 (Inditop.com) A terror alert was Monday sounded in Delhi, Mumbai and Kolkata following intelligence reports of possible suicide attacks on vital installations in these cities.

Home ministry sources said the inputs claimed that trained suicide squads have sneaked into India to carry out these attacks.

Security has been tightened at airports, public places and iconic structures in these cities.

Last month, ahead of the first anniversary of the 26/11 attacks, a similar alert was sounded by intelligence agencies in key coastal cities.

Mumbai, Kolkata, Bangalore and coastal Gujarat were among the places put on alert by the Indian Navy then.