Various Union ministers have slammed West Bengal chief minister Mamata Banerjee after she challenged Prime Minister Narendra Modi to go for an UN-monitored referendum on the Citizenship (Amendment) Act (CAA) and the proposed nationwide National Register of Citizens (NRC) exercise.

Union textile minister Smriti Irani, who was in Kolkata on Friday, criticised the chief minister, saying that the remarks were an insult to Parliament.

'The comment (made by Banerjee) is an insult to Indian Parliament,' Irani told reporters when asked to react on the Trinamul supermo’s remark over the citizenship law.

Union minister of environment, forest and climate change Prakash Javadekar demanded that Banerjee apologise for the comments on the act.

The controversial act has sparked off various protests across the country.

'It is shocking that Mamata Banerjee is talking about referendum. Who is the UN body to monitor the referendum? This is an insult to the 130 crore people of the country and their mandate. Mamata should apologise,' Javadekar told reporters.

The Union minister further said that some people were trying to create confusion over the legislation.

'CAA is about inclusion and not exclusion. They are talking the language of Pakistan. There are some elements who are causing confusion. We are trying to reach out to people with the right approach,' he said.

Union minister of state for home affairs G. Kishan Reddy dubbed Banerjee’s remarks “irresponsible”, saying that the international community has nothing to do with the CAA.

Reddy maintained that the India gave citizenship to many immigrations before as well.

'Earlier also we gave citizenship some people from Pakistan and Bangladesh during the past five and a half years. Muslims were also given (citizenship). This (CAA) is not against any religion or region,” Reddy said.

'Mamata Benerjee is irresponsibly seeking the involvement of the United Nations. This is inviting foreign countries to interfere in our affairs,' Reddy told PTI over phone.

'I don’t know why she is making such irresponsible comments as the chief minister of a state, he added.

He added that the central government is keeping a close watch on the law and order situation in various states.

Security has been tightened in various states after protests were held across multiple cities in the nation and at least three people died in police firing in BJP-ruled states.

'We have regularly been giving instructions to states. So far, we have given advisories twice. Law and order is a state subject. We have asked them (states) to be vigilant and ensure that the law and order is under control,' he said when asked about the protests in some parts of the country.

Reddy said the northeast, which witnessed large scale protests over the CAA is 'peaceful' and blamed some individuals and political parties for the unrest in some places.

In a rally on Rani Rashmoni Avenue in Kolkata on Thursday, banerjee had dared the BJP to hold a UN-monitored referendum on the amaneded citizenship law and the proposed nationwide NRC.

'If BJP has guts, it should go for a UN-monitored referendum on the amended Citizenship Act and NRC. If the BJP loses this mass vote, then it should step down from the government,' she had said.