Bangladeshis living in India say the passage of India's controversial citizenship law and the proposed National Register of Citizens (NRC) has created a "growing climate of hostility" towards Muslims, causing an increase in the smuggling of people along the India-Bangladesh border.

In December, the Indian parliament passed the Citizenship Amendment Act (CAA) to grant nationality to "persecuted" minorities from three neighbouring Muslim-majority countries: Bangladesh, Pakistan and Afghanistan.

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Deemed anti-Muslim by critics for making religion a marker of citizenship in an officially secular country, the anger over the CAA and fears over the NRC have triggered protests across India, which have seen an unprecedented participation of Indian Muslims.

Meanwhile, Bangladeshi Muslims, with some living in India for decades, told Al Jazeera that the recent developments have generated "hostility" against them and has forced them to flee the country, often with the help of smugglers.

Those fleeing fear that if they do not leave, the Indian government will send them to various detention centres operating in the Indian state of Assam and in other parts of the country.

Forced to flee

Reporting from the Bangladesh side of the 4,000 kilometre (2,500 mile) border the two countries share, Al Jazeera's Bernard Smith said smuggling of people has suddenly become a booming business.

Smith reported an influx of people along the border in recent months, with most traffic going in one direction - from India to Bangladesh.

"It is impossible to say exactly how many people are illegally crossing the border from India into Bangladesh," he said, adding that the border force has arrested at least 500 people in the last couple of months.

"Smugglers tell us they are crossing 40-60 people every night," he said.

Munir Hawoldar, a recent returnee in his late 20s, told Al Jazeera he had been living in India since he was an infant.

"They have been cracking down and there have been arrests. Sixty people from our community were detained. We haven't heard from them. This caused panic and we decided to leave for Bangladesh," he said.

Flashing what she said was an Indian work permit, Kuki Begum said she had been living in India with her husband for 11 years.

"It is absolutely clear India's ruling party doesn't want any Bangladeshi anymore," she said. "What can we do? We have to live with our dignity and honor, so we came back."

Last month, hundreds of people were rendered homeless after Indian authorities demolished a slum in Bengaluru city over rumours it was inhabited by Bangladeshis. It later turned out that all the slum residents were Indian citizens.

According to the Indian government, some two million Bangladeshis live in India.

Last month, Bangladeshi Prime Minister Sheikh Hasina said in an interview she "did not understand" why the Indian government passed the CAA, adding that "it was not necessary".

Bangladesh is already struggling to cope with 1.2 million Rohingya refugees from Myanmar who fled what the United Nations calls a genocide that took place in 2017.