Kolkata: A Catholic school in West Bengal has sought police protection after it received four letters threatening to burn it down.

Security has been stepped up at St Capitanio Girl’s Higher Secondary School, about 70 km from Jalpaiguri town, said Ravindra Nath, a senior police officer.

The letters written in Hindu and found near the girls’ hostel have asked the nuns to leave the area immediately. If they nuns fail to comply, their school as well as a nearby church would be burned down, the letters have warned.

Policemen are on a round-the-clock vigil at the school in north Bengal since Sunday after the school headmistress, a nun, filed the police complaint, reported ndtv.com.

The first letter was found on March 11, three days before the attack on a convent school at Ranaghat in south Bengal, where a 72-year-old nun was raped.

The letters were found near the stairs at the hostel entrance, which is well guarded. Initially, they were seen as a prank but after the Ranaghat incident, the police began to look at them seriously.

Senior officers visited the school on Tuesday to review security.

The heavy police presence has left many students and teachers nervous as they have not been clearly informed about the problem.

The school is more than 50 years old and has around 1,700 students, almost 200 in the hostel. The Church also manages a boys’ school nearby.

In recent months, there have been many attacks on churches and Christian buildings across the country.

“I will go to any extent to protect minorities. I will do everything to end the sense of insecurity prevailing among minorities,” said federal Home Minister Rajnath Singh on Monday.

On Tuesday, four men were arrested for allegedly vandalizing a church near Mumbai over the weekend. A group of activists attacked a church and a convent in Jabalpur in Madhya Pradesh last week.