India's prime minister Narendra Modi has asked the police to intervene in a series of attacks against Christian institutions after a burglary at a convent school in the capital.

The break-in was the sixth attack of its kind in three months. The vandalism includes an arson attack on a Delhi church last December.

Protesters have accused Hindu nationalists of being behind the attacks but the police claim there is no evidence of this.

Previously silent on the attacks, it is thought the prime minister could be trying to win back the Christian vote in India after he received a drubbing in elections in Delhi last week.

The Aam Aadmi Party, whose name means as "the common man", won 67 of the 70 assembly seats in the Delhi state elections last Tuesday elevating party leader, Arvind Kejriwal, to chief minister of Delhi. Modi's own Bharatiya Janata party was left with just three seats.

According to local reports, the election was marred by anti-Catholic violence. Churches were attacked and police were accused of being heavy-handed after they broke up a peaceful protest. One nun was shown on television lying on the ground outside the Sacred Heart cathedral as police attempted to haul her onto a bus.

After the attack on the Holy Child Auxilium convent school on Friday, Modi called in Delhi Police Commissioner BS Bassi and ordered him to take strong action against "rising crime and vandalism in Delhi."

Modi also ordered his home secretary LC Goyal to monitor the police action.

It is highly unusual for the prime minister to summon the head of police directly. The police and the government have been accused of doing too little to help the Christian community and the anger among voters is thought to have aided the Aam Aadmi party.

Mr Bassi said: "I was summoned by the Prime Minister, who asked me to enquire into the Vasant Vihar school incident. He felt anguished about the recent attacks on places of worship of the Christian community."

Mr Kejriwal, who was sworn into his office last Saturday, tweeted on Friday: "I strongly condemn the attack on Holy Child Auxilium school. These kinds of acts will not be tolerated."

His later tweet pledging to devote himself to finding "systemic" solutions to Delhi's problems was retweeted 1,500 times.

Father Savarimuthu Shankar of Delhi's Catholic archdiocese told Delhi television: "Our only demand is we want justice and we want protection for all our churches. We want to be safe and secure. We are not demanding as Christians, we are demanding as citizens of India."

Referring to the government, he added: "You are not able to protect a small municipal minority, how are you going to protect the whole of India?"