New Delhi: Following intelligence report on a possible use of three-wheeler autos by terrorists to carry out massive attacks in Delhi, three-wheelers in the nation's capital have come under the security scanner. Highly placed government sources says there are intelligence inputs on the possible use of autos for triggering a blast in a crowded area of Delhi, reported The Economic Times.

The Intelligence Bureau has also asked Delhi Police to step up security at vital installations in the capital after an email, which police sources said was signed by the 'Deccan Mujahideen'. The email warned of a repeat of the Mumbai terror attack at Indira Gandhi International Airport and the three major railway stations.

Reacting to the threat, police are conducting random checks on autos, particularly around the airport.

According to experts, since three-wheelers run on CNG, an 'auto bomb' is likely to cause more damage than an explosion in a petrol or diesel vehicle.

"The information said that explosives in an auto were likely to be planted and set off in a crowded area. After that, the airport security guards have been checking on idle autos and those which enter the premises without passengers. The threat still holds and checking has been intensified," said a government source.

DCP (IGI Airport) Sanjay Kumar said they had received a communique from IB about stepping up vigil at the airport.

"We are already on high alert and security has been beefed up in the area. We are coordinating with NSG. While CISF is also checking vehicles, specially on the approach roads to the airport and has increased surveillance at various points, the Delhi Police has increased its deployment in the area as well. Airlines have also been asked to beef up security wherever required."

The Indian Railways too is stepping up security at all stations in Mumbai and Delhi. "Keeping the CST shootout in mind, we plan to increase security at all stations on our network. This will include 17 Metro stations. Some of the new equipment, to be installed soon, include electronic access control systems which will be set up under the build, own, operate and transfer model (BOOT). In addition, the dog squad will be strengthened and CCTVs with at least 30 days of storage capacity will be installed," a senior police officer said.