An angry mob of Hindu nationalists stormed a Catholic school on Monday, throwing stones and damaging property in protest of alleged conversions at the school, officials said Tuesday.

Brother Anthony Tynumkel, the administrator of St. Joseph's School in the city of Ganj Basoda in Madhya Pradesh, said a mob of at least 200 people came in through the school gate shouting slogans favored by radical Hindu nationalists.

"Some of them turned violent and threw stones and damaged property. We shifted the students to the top floor so they were safe. After some time, they left," Tynumkel said, adding that the school had been conducting the year's final examinations when the incident occurred.

The mob is believed to have been whipped up into a frenzy by a letter circulated on social media that claims eight pupils were converted to Christianity at St. Joseph's on Oct. 31.

The accusations were untrue, according to Tynumkel: "We don’t have any attendance on Sundays, and the students named do not study here."

"The police have detained four people, more will be identified through CCTV. We have posted additional security at the school and adjoining church. All employees, children, the nuns – everyone is safe," said local government official Roshan Rai.

Rai said all those responsible for the vandalism would be punished, but also confirmed that a probe had begun into the alleged religious conversions.

While voluntary religious conversion is legal in India, right-wing Hindu groups have long accused Christians in the country of luring the poor to join churches in exchange for education and other advantages.

Monday's incident is the latest in a string of attacks on churches and Christian institutions reported across India.

In recent weeks a Christian prayer meeting was disrupted by Bajrang Dal activists in the town of Belur and a church was vandalized in New Delhi’s Dwarka area.

Local Hindu far-right outfits have been demanding a probe into the alleged conversions, NDTV news channel reported. "If the school's involvement is found, it should be bulldozed," Bajrang Dal leader Nilesh Agrawal was quoted as saying.

Hindu mobs also target Muslim places of worship in violent attacks.