Airports in India could be targeted by terrorist using "dirty bombs", a lethal cocktail of conventional explosives and low-grade radioactive material designed to spread radiation over a wide area.

A recent threat assessment survey conducted by the CISF, which guards 54 airports including those in Delhi, Mumbai, Chennai and Kolkata, has listed chemical and biological attacks as one of the threats apprehended by the force.

Senior CISF officials are of the view that procuring radioactive substances has become relatively easy since the
break up of the Soviet Union, and terrorists laying their hands on such materials could not be ruled out.

"Now that reports emanating from various quarters speak about Al Qaeda's presence in India, dirty bomb attacks
can be a possibility, though it is still a futuristic projection," an officer told PTI.

The force has favoured the procurement of an array of gadgets, including decontamination kits, multi-gas detectors,
battery-operated samplers and anti-gas respirators to deal with such attacks.

The survey, conducted once in two years, was aimed at identifying various threats faced by airports, nuclear
establishments, government buildings and other vital installations guarded by the CISF.

The report assumes significance in the wake of the unearthing of a terror plot in Britain to blow up flights mid-air by using explosives that could be made by mixing readily available substances like gels.

Other threats identified by the CISF are armed attacks, sabotage, hijacking, suicide bombing and IED blasts, most of
which can be thwarted by tightening perimeter security and putting in place stringent access control measures.

The CISF has decided to install imported state-of-the-art explosive detection equipment and automated access control
system using biometric readers to tighten security.

As part of an upgradation, the force is mulling the installation of GPS-enabled vehicle monitoring systems to track traffic within airports, senior officials said.

The mechanism could also be used to locate key personnel, they said.

The CISF also plans to install more X-ray machines at the Delhi and Mumbai airports once repair work being carried out there by the GMR and GVK-led consortiums is completed.

The force feels the existing security mechanism in both airports is inadequate in view of a sharp increase in
passenger volume after the advent of low-cost airlines.

"The security apparatus has to be fine-tuned and we are waiting for the revamp of the Delhi and Mumbai airports. The
private owners are also keen to upgrade the security system," a senior official said.