Indian Christians have held prayer vigils across the country in protest against the rape of a nun in an attack on a convent school in West Bengal. Although the motive for the assault is unclear, it is seen as part of a growing trend of attacks on minority groups in the country, which includes the demolition of a church under construction in Haryana, in the north, on Sunday.

Prime Minister Narendra Modi today condemned both the rape of the nun and the church demolition, and said he had called for an immediate report on the violence.

But Modi, who leads the Bharatiya Janata Party (BJP) which has close links to Hindu nationalism, has been criticised in the past for his perceived reluctance to take a clear stand against the intimidation of minority groups. Although there have been numerous reports of forced conversions and attacks on churches in recent months, it wasn't until February that Modi made a public statement in support of religious freedom.

"If you look at the last eight months since the BJP came to power, we've seen a growing trend of attacks on religious minorities – both the Christians and the Muslims," Christian Solidarity Worldwide's South Asia spokesperson told Christian Today.

Apart from the attacks this weekend, there have been several incidents of churches being vandalised, and in February, 20 Christians were detained and beaten by police after handing out evangelistic leaflets in Hyderabad.

Prominent Christian commentator and retired police commissioner, Julio Ribeiro, wrote in the Indian Express this week: "I feel threatened, not wanted, reduced to a stranger in my own country."

Although India has not seen any recent large scale attacks, such as the anti-Christian violence in Orissa in 2008, CSW's spokesman said the current spate of small-scale attacks by fringe groups was also concerning.

"I believe from what we've heard that... the BJP having an overall majority has given these fringe groups that sense of 'majoritarianism' – that sense of being in control and [thinking] 'Let's bring the country back to what we believe it was before'," the spokesperson said.

"They've been promoting a shift away from a secular state, to a more extreme form of Hindu ideology, and it's being done with a sense of impunity."

CSW is concerned that although these incidents have been reported to the police, they have often not been registered and properly investigated.

Police in West Bengal told Reuters that they had detained five of seven men who broke into the convent, although the man suspected of rape has not been caught. Indian parliamentarians have expressed anger over the failure to make an arrest.

The nun attacked on Saturday was discharged from hospital on Sunday night. She has reportedly asked for God to forgive her attackers and appealed for peace.

The CSW spokesman said it was important for the Indian government to condemn such attacks as soon as they occur, and demonstrate a commitment to seeing justice for the victims of violence.