Police are planning to procure bomb jammers from Israeli and American firms to prevent terror attacks on VIP convoys.

The Maoist threat prompted state police to ask five foreign companies to provide technical details of gadgets that can prevent activation of improvised explosive devices (IEDs) through remote control by blocking the signals, said sources.

To expedite the purchase, officers of the Special Security Unit have gone to New Delhi to hold talks with Indian representatives of the Israeli and American companies, said a senior officer.

Representatives of the companies have been asked to reach Calcutta by next week with the data sought for “technical evaluation”. The final call on the jammers will be taken after assessing the “technical bids”.

“We are looking to purchase jammers and will proceed according to the state government’s directions,” said A.K. Maliwal, the director of security.

State police, which already have mobile jammers that can prevent explosions from being triggered using cellphone signals, are also looking to procure more advanced mobile jammers. Uttar Pradesh is one of the other states that has imported advanced mobile jammers from Israel.

“An advanced convoy jammer costs between Rs 1.5 crore and Rs 2 crore. They are effective against roadside bombs, radio-controlled mines and remote-controlled explosives hidden in or near vehicles in a convoy,” said a senior officer.

The police were tightlipped about the number of jammers they were planning to procure.

Security agencies had proposed an upgrade of gadgets used for VIP security after the attack on the chief minister’s convoy in Salboni last November. Intelligence agencies have warned that Maoists could attempt an attack on Buddhadeb Bhattacharjee’s convoy in Calcutta.

What are jammers?

Portable gadgets that prevent improvised explosive devices (IEDs) from being set off using remote control. Jammers work by stopping signals from reaching the IED. While convoy jammers protect moving VIP vehicles, cellphone jammers only work when they are at rest.