Kolkata, Dec 11 (IANS): Security agencies, both central and state, have beefed up surveillance at the International Maritime Boundary Line (IMBL) with Bangladesh in West Bengal, apprehending illegal crossover of Bangladeshi citizens including member of underground outfits who had become active again amid the ongoing crisis there.

Sources said that the decision to beef up surveillance has been taken following two recent developments, the first being two Bangladeshi marine vessels being nabbed for crossing the IMBL and entering the Indian waters illegally.

Intelligence inputs are that besides the porous land borders with Bangladesh in certain pockets of West Bengal, there might be attempts of illegal crossover using the maritime borders and subsequently spreading across to different parts in the state.

The second development, sources added, is the Intelligence input that of late some members of the terrorist organisation Hizb-ut-Tahrir (HuT) are trying to become active in the bordering districts of West Bengal with Bangladesh and making attempts to set up sleeper cells there.

The two most sensitive bordering districts on this count as identified by the Intelligence agencies are Malda and Murshidabad, both being minority-dominated.

Also under surveillance is another border district of Nadia, which has already been identified by the security agencies as the hub for creating fake Indian identity documents for Bangladeshi citizens illegally crossing over to the Indian territory.

Intelligence agencies, sources added, have also got specific information that two active HuT associates recently came to West Bengal with valid Bangladeshi passports posing as students and had meetings with some local youths in Malda and Murshidabad districts.

These two HuT activists, as per Intelligence inputs, initially held conversations with the local youths in these two districts over religious issues and thereafter carried on the conversation to the level of opening sleeper cells in the bordering districts.

These two Bangladeshi citizens interacting with the local youth have been identified as Ridwan Maruf and Sabbir Amir.