Eight residents of West Bengal’s Cooch Behar district, who were detained in Delhi on the suspicion of being “illegal” Bangladesh migrants, were released on Tuesday. They were members of families who had relocated to India in the 2015 enclave exchange between India and Bangladesh.

All eight were detained by the police on Monday from a brick kiln in Haryana during a drive against undocumented migrants, Deputy Commissioner of Police (Northwest Delhi) Bhisham Singh told The Indian Express.

They were released on Tuesday, their family members told Scroll.

The release came after the eight migrants produced their resident cards issued by the West Bengal government and other relevant documents, Singh added.

Those who were detained were identified as Samsul Haque and his brother Rejaul Haque, Muhammad Rayhan Haque, Muhammad Rabiul Haque, and his wife Rashida Begum, the newspaper reported. Rabiul’s three children were also detained.

Their family members told The Indian Express that all eight are from Dashiar Chhara, a former Indian enclave in Bangladesh. They had moved to an apartment complex in Cooch Behar’s Dinhata area made exclusively for enclave dwellers who had come to India after the exchange in 2015.

Their release came the police in Cooch Behar district police contacted their counterparts in Delhi.

Samirul Islam, chairperson of the West Bengal migrant welfare board, claimed that such detentions were happening daily to migrants from the state. He alleged that police in Bharatiya Janata Party-ruled states and in Delhi do not bother to inform the state government about such cases.

“We, on our own, have made verifications and sent them the requisite documents,” The Indian Express quoted Islam, also a Trinamool Congress MP, as having said. “In this case, the district administration got in touch with the Delhi Police authorities.”

He added that Prime Minister Narendra Modi and Chief Minister Mamata Banerjee had welcomed the families to India after the enclave and exclave exchange in 2015.

“Now they are being detained as illegal Bangladeshi citizens,” he was quoted as saying. “And that too in the national capital.”

The exchange of enclaves and exclaves took place on August 1, 2015. Under this agreement, 111 Indian enclaves covering 17,160 acres inside Bangladesh were transferred to Bangladesh, while 51 Bangladeshi enclaves occupying 7,110 acres in India became part of India.

The residents of these enclaves were given the option of accepting citizenship of either country. At least 921 residents opted to move to the Indian side.

The incident came as Indian authorities have been pursuing a policy to force individuals claimed to be undocumented migrants into Bangladesh. In June, four men from West Bengal, who were forced into Bangladesh on allegations of being undocumented migrants, were brought back.

India has pushed back more than 2,000 persons into Bangladesh since the country launched “Operation Sindoor”, a military operation in May against terrorist camps in Pakistan and Pakistan-occupied Kashmir.

The legality of the “push back” policy has been debated in India and internationally. Experts have told Scroll that the policy violated India’s obligations under international law and customary international law.