NEW DELHI » A nun in her 70s was raped during the robbery of a convent school in West Bengal, India, before dawn Saturday, police and church officials said.

There were contradictory accounts in the hours after the attack, with some Indian news outlets describing the attack as a gang rape. Angry crowds, including some convent students, blockaded a railway line and a highway near the site of the crime, some 40 miles north of Kolkata.

Thomas D’Souza, the Catholic archbishop of Kolkata, said in a telephone interview that one man had raped the nun. He said six men armed with knives had broken into the Convent of Jesus and Mary in Ranaghat and "ransacked the place," taking away whatever cash they could find.

He said the robbers tied up the security guard, then forced their way into the convent, where one of them raped the nun. He said other nuns were tied to chairs at the time.

The woman, he said, "had to have surgery," but is now out of danger. P.B. Salim, the ranking civil servant of Nadia district, where the attack took place, also described the crime as a single rape, as did A. Ghosh, the district police chief.

The robbers stole around $9,000 in cash and valuables from the convent, Ghosh said.

Mamata Banerjee, the chief minister of West Bengal, said she had ordered the Crime Investigation Department to examine "all aspects to this horrific crime."

The per capita rate of rapes reported to the police in India is far below that of many developed nations, but a series of especially terrible attacks in recent years has prompted intense national debate about the problem of sexual violence.

The most notorious among those crimes was the gang-rape of a physiotherapy student on a bus in New Delhi. The release of a British-produced documentary was recently blocked in India by the government, which argued that an unrepentant interview by one of the convicted rapists could incite street protests.

D’Souza said he believed the attackers’ primary motivation was greed, and that he saw no evidence of a religious motive.

"The spontaneous reaction is certainly one of shock," he said.