A nun in her 70s has been gang-raped by a group of bandits when she tried to prevent them from robbing a Christian missionary school in eastern India, police said.

The nun was hospitalised in serious condition after the attack, which was committed by seven or eight men at the Convent of Jesus and Mary School in Nadia district, 80 kilometres northeast of Kolkata, the capital of West Bengal state, a police officer said.

The men escaped and police are searching for them, said the officer, who spoke on condition of anonymity because he was not authorised to talk to reporters.

The robbers tied the school's security guards with ropes early on Saturday and entered the nuns' room, where the women were sleeping. They took one of the nuns to another room when she tried to block their way and then raped her, the officer said.

The woman who was attacked is either 71 or 72 and is the oldest nun at the school, he said.

The men escaped with some cash, a mobile phone, a laptop computer and a camera, all belonging to the school, the officer said.

They also ransacked the school's chapel and holy items, the Press Trust of India news agency cited the archbishop of Kolkata, Thomas D'Souza, as saying. 

Scores of angry students, their parents and teachers blocked a nearby highway and railroad tracks for several hours demanding swift police action leading to the arrest of the culprits.

Mamta Banerjee, the state's top elected official, strongly condemned the attack and ordered a high-level police investigation. D'Souza appealed to people to maintain peace and harmony in the area

Source: AP