New Delhi: In the wake of the deadly car bomb blast in Delhi, Kolkata Police has intensified city-wide surveillance, focusing on identifying nationals from Bangladesh, Pakistan, and Afghanistan who have not returned home after their visas expired.

Focus on Hidden Foreign Nationals

Police sources said teams are investigating whether any citizens from these countries are currently hiding in Kolkata or remote districts.

The immigration department has also begun cross-verifying records of expired visas and fake identities.

Old Sleeper Cells Under Watch

Detectives have revived investigations into dormant sleeper cells of militant organisations operating in and around the city.

Officers suspect that some overstaying foreigners may have links to these networks.

Fake Identity Cards and Security Threats

Investigations have revealed that several overstaying nationals have procured fake Indian identity cards to secure employment and residence.

Recently, three Afghan nationals were arrested from South Kolkata for living under false identities.

Intelligence on High Alert

Police believe that some of these individuals may have ties to extremist groups. Efforts are underway to trace their hideouts, with intelligence agencies keeping a close watch on released members of militant outfits and potential reactivation of sleeper cells.