The National Register of Citizens exercise was needed in India, and it should be first undertaken in West Bengal as infiltrators have become the vote bank of the Mamata Banerjee-led ruling Trinamool Congress, state BJP chief Dilip Ghosh said here on Thursday.

However, Ghosh pointed out that he was not saying that the BJP-led NDA government will undertake that exercise.

"NRC is needed in India. The first NRC exercise should be undertaken in Bengal. When and how it will take place, or whether the Supreme Court or the government will do it... for instance, the BJP has no connection with the NRC in Assam.

"When Rajiv Gandhi was Prime Minister, he had signed the Assam accord, which talked about carrying out an NRC exercise. He didn't do it. Disappointed people went to court, and as per the judiciary's order, the NRC was done," the MP said.

Regarding a possible NRC in the state, Ghosh said: "First let the Citizenship Amendment Act (CAA) be implemented in the state, then we will see what to do with NRC. We are not saying we will implement it but we feel it should be to weed out infiltrators who have become the vote bank of the Trinamool."

Daring Banerjee to stop implementation of the CAA, he said "it is a central act which will be implemented across the country. Let Mamata Banerjee stop it if she can from coming into force in the state".

On Sunday, addressing a huge rally in Delhi's Ramlila ground, Prime Minister Narendra Modi had said his government has never discussed the issue of carrying out a nationwide NRC since coming to power in 2014.

The Trinamool latched on Ghosh's comments, with its Secretary General Partha Chatterjee saying: "The cat is out of the bag."

The CAA seeks to provide Indian nationality to Hindus, Christians, Sikhs, Parsis, Jains and Buddhists fleeing to India from Pakistan, Afghanistan and Bangladesh due to persecution before December 31, 2014.

As per the Act, such communities will not be treated as illegal immigrants now and will be given Indian citizenship.

The legislation has led to intense protests in most parts of the country, and over 20 people have died during the agitation so far.

In Bengal, trains, buses and railways stations had been torched and vandalised, and roads and train tracks blockaded by the protesters soon after the legislation was passed in the Parliament.

Over the past eight days, the Trinamool has been bringing out rallies and holding processions all over the state. Banerjee has been spearheading the movement, and has led five marches in Kolkata and its twin city Howrah.