Procuring ration card, passport, voter ID cards and documents to establish their Indian citizenship are easy and sleeper cells help illegal immigrants in getting them.
The slain militants are believed to be members of Jamatul Mujahideen Bangladesh.
Director of Intelligence Bureau Syed Asif Ibrahim on Sunday said effective intelligence sharing with neighbouring countries like Nepal, Myanmar, and Malayasia, Saudi Arabia would go a long way in helping the country tackle the threat from global terror groups like the Al Qaeda and ISIS.
Of the four terrorists, two including a woman were killed on Monday. The bodies of the female terrorist and one man were handed over to police but two others were inside as they were wired or surrounded by explosives.
However, the US praises India for its significant counter-terrorism actions.
The PFI is alleged to have been continuously involved in anti-government propaganda and spreading the narrative that Muslims were being persecuted in India.
'Now that an extremist organisation like the PFI has been banned, it is time for the leaders to reach out to the minority community.' 'You need to have co-ordination between the State and the social fabric to send out the message that it is not directed at the community, and they should not feel vulnerable.'
The outfit has prepared a list of local Hindus and secularists who they plan to target.
Neo-Jamaat-ul-Mujahideen's wanted leader Nurul Islam alias Marjan and another unidentified extremist were killed by Counter-Terrorism and Transnational Crime unit in Mohammadpur Beribadh area of the capital.
13 of the 17 militants who were presumed to have plotted the attack were killed in encounters so far, said police.
The attack on the Mahabodhi temple is a precursor before Pakistan-based terror outfits launch a major 'war' in support of Myanmar's Rohingya Muslims, reports Vicky Nanjappa
Meanwhile, Union Home Minister Rajnath Singh said the state governments have been asked to identify Rohingya refugees in their regions and collect their biometric details.
The Bangladesh government on Sunday claimed the attackers who slaughtered 20 hostages inside a cafe in Dhaka in the country's worst terror attack were members of "homegrown" Islamist terrorist outfits and not Islamic State of Syria and Iraq militants.
'A deadly combination of money and religion lures them into the murky world of terrorism.' 'You will reach heaven if you kill -- what a doctrine!' Professor Ajoy Roy, whose son blogger Avijit Roy was brutally murdered in Dhaka last year, tells Rediff.com's Indrani Roy.
The Sheikh Hasina-Narendra Modi summit put India-Bangladesh ties on a firmer pitch. Brigadier S K Chatterji (retd) takes stock.
About 17 lakh investors, mostly in West Bengal, who have lost crores of rupees in the Saradha chit fund scam are fast losing hope. The scandal continues to roil West Bengal political circles with several ruling Trinamool Congress leaders being implicated and some arrested. Even West Bengal Chief Minister Mamata Banerjee's name has been dragged into the sordid mess. Indrani Roy presents a FAQ on what the scam is about and the main players behind it.