A group of 20 Indian Christians have claimed that they were detained and beaten by police while on a mission trip in Jaipur, Rajasthan, in northern India.
They said the incident took place last Thursday after they had been distributing pamphlets, Indian news site NDTV reports.
The group, who are from the Hebron Church in Hyderabad, said they had faced some difficulties from the community where they were witnessing. They left the area but were pursued by locals, who then reported them to the police.
Surendra Kumar, one of the group, told NDTV: "The police picked us up and took us to the police station. We were made to get out of the police van by being kicked and then, inside the police station, the cops lined us up and hit us with belts on our hands and wrists."
Human rights advocates have said that the police should have taken action against those who harassed the missionaries, rather than the Christians themselves.
The People's Union for Civil Liberties (PUCL) has taken up the case and is calling for the suspension of the police involved in the incident.
The police refused to comment on the incident to NDTV although they did acknowledge that it had taken place.
Religious freedom in India has come under increased scrutiny in recent months, with numerous reports of forced conversions to Hinduism.
Prime Minister Narendra Modi said in a speech on February 17 that his government would protect religious freedom.
"My government will ensure that there is complete freedom of faith and that everyone has the undeniable right to retain or adopt the religion of his or her choice without coercion or undue influence," he said.
But although many welcomed his support for religious freedom, some have said Modi may have been addressing Christian missionaries in India, and not the radical nationalists credited with supporting the forced conversions.
The head of the Hindu nationalist organisation Rashtriya Swayamsevak Sangh (RSS), Mohan Bhagwat said on a visit to Rajasthan last week that Mother Teresa's work in India was motivated by wanting to convert people to Christianity.
"Mother Teresa's service might have been good," he said. "But there was a motive behind it – to convert the person being served to Christianity."
General secretary of the PUCL Kavita Srivastav said: "Bhagwat arrives in Rajasthan and makes a statement about Mother Teresa vitiating the minds of ordinary persons. And within 24 hours of that statement, we see here that a group of 20 people who are spreading literature about Christ and talking to people, are not just harassed by Hindutvawaadi [nationalist] elements and picked up by the police as if they are the culprits, but they are also pushed, kicked and beaten inside the thana [police station]."