Hindu extremists have turned a church in the Indian state of Uttar Pradesh into a temple and Christians say its members have been forcefully converted  to Hinduism.

Dalit Christians had worshipped at the Seventh Day Adventist church in Asroi village in Aligarh district, 160 kilometres (100 miles) south-east of New Delhi, Barnabas Aid reported on September 19.

Dalit Christians belong to India's lowest caste, one known as "untouchables."

The church was "purified" with a ritual and declared to be a temple by the Hindu extremists.

During the purification ritual, Barnabas reported that the cross was torn down and a poster of the Hindu god Shiva was placed inside the church building.

The Hindu extremists then released a YouTube video and a press release claiming that 72 low-caste Christians had returned to Hinduism.

"This is mere propaganda and a ploy to intimidate Christian congregations as a whole. Saffron (Hindu extremist) groups are behind it," Sundar Singh, a Dalit Christian activist reported.

He was speaking at a meeting aimed at drawing national attention on the atrocities against Christians.

In Aligarh, Christians fear there will be more takeovers in the coming months as they feel the administration is doing nothing to protect them.

Advocate Osmond Charles had told the Times of India on August 29, "The havan [ritual] took place inside the church. Christians don't feel safe regarding their properties.

"Tomorrow, another church may see a 'shuddhi karan' [purification] exercise. The issue is not about leaving a faith, but about maintaining the sanctity of a place of worship."

But while the Christians are outraged with what happened, members of the Dharam Jagran Vivad, Aligarh, who conducted the re-conversion ceremony of the Valmikis, are unmoved.

Khem Chandra, a local member of the Vivad group, told the India Times, "We will think about the church building. It belongs to the missionaries, but the ground on which it stands belongs to Hindustan.

"We will not compromise on our dharti (earth). We will meet the villagers and decide about the temple."

More than 600 attacks on minority Muslims and Christians have been reported during the first 100 days of the new government led by Prime Minister Narendra Modi who leads the Hindu nationalist BJP party.