It was a neighbour, a man Father Thomas Chellan knew well, who went to search for a tyre to set alight around the 57-year-old priest’s neck. One of the first victims of the antiChristian pogroms that have swept India for the past two months, he had already been beaten to his knees, stripped and doused with paraffin by the Hindu mob who had dragged him from his hiding place. “From now, you will pray only to Ram,” shouted his attackers, their foreheads smeared with blood-red vermillion.

As one of the mob fumbled with a box of matches, the 28-year-old nun the priest had been hiding with in the village of Nuagaon in the remote jungle state of Orissa was hauled away. In a police report filed the next morning she said she was gang-raped by four men.

Father Thomas’s life was saved when one of the mob suggested that the priest be burnt alive farther down the street “where more people could see”. The mob agreed and moved on but failed to settle on a new site. “I thought, my God, now I’m going to die,” Father Thomas said. “For these people, Christians are like animals.”

Many Indians are shocked but few are surprised by the horrors in Orissa — a wave of murder and arson that has claimed 60 lives, destroyed more than 4,000 houses and left as many as 50,000 Christians homeless.

Religious violence is on the rise across the country, setting Muslims, Hindus, Christians and even nature-worshipping animists against each other, ahead of a general election expected in March. This week Manmohan Singh, the Prime Minister, gave warning that the upsurge in interreligious strife threatens to destroy the “fundamental underpinnings” of the world’s largest democracy.

Already the worlds of hundreds of families in Orissa have fallen apart. The Christians in the state’s squalid, under-resourced refugee camps say that they have been warned not to return home unless they convert to Hinduism. One priest described how his father had been forced to denounce his faith with an axe pressed to his throat. There are dozens of similar stories of forced conversions.

At the most local level, the Orissa atrocities owe much to a longstanding rivalry between the two desperately poor communities that dominate Kandhamal, the district of the state that has witnessed the worst violence: the Pana dalits (or untouchables) and the Kandha adivasis (or tribals).

Over several generations the Panas have moved towards Christianity after coming into contact with Roman Catholic, Baptist and, more recently, Pentecostal missionaries. The Kandhas, meanwhile, gravitated to Hinduism.

The two groups compete for scarce resources in Orissa, one of India’s very poorest states. Tensions between them escalated when the Christian Pana community began to better themselves through education and were heightened further when the Panas began to demand Scheduled Tribe status, which would qualify them for benefits available only to Kandhas.

Meanwhile, national extremist Hindu groups have stoked the Kandhas’ anxieties by claiming that foreign-backed Christian missionaries are engaged in a campaign of forced conversion in Kandhamal. The 500 refugees in the dilapidated YMCA building in Bhubaneshwar, the capital of Orissa, were in no doubt as to the loyalty of the Hindu fanatics who razed their villages and killed their relatives. Asked who was responsible for their plight, group by group they hissed: “RSS, RSS.”

That stands for Rashtriya Swayamsevak Sangh (or National Volunteers’ Organisation). Founded in 1925 and enormously influential, the RSS’s stated mission is to transform constitutionally secular India into a wholly Hindu state. Some say that it is using Orissa as a “laboratory” to test its tactics.

For decades the organisation has polarised India. It is remembered fondly by many for the support it gave to millions of destitute Hindus during Partition. Others say it resembles the Mafia, the Black Shirts and the KKK, and note that it trained Nathuram Godse, the Hindu radical who assassinated Mahatma Gandhi.

Now, with its sister organisations Vishva Hindu Parishad (VHP, its theological offshoot) and Bajrang Dal (a youth wing), the RSS stands accused of inciting and even organising Orissa’s anti-Christian uprising.

The All India Catholic Union (AICU) says that it has collected witness reports from dozens of victims in Orissa who identify their attackers as members of the Bajrang Dal. The AICU says that the Bajrang Dal provides the RSS’s “stormtroopers” and that its members are identifiable by their chants, their orange bandannas and flags and their trident daggers.

Amid mounting calls for the body to be banned, the Central Government in Delhi says that it is “very carefully and actively watching activities of Bajrang Dal” and will take appropriate action at the appropriate time.

Many say that time has passed, but that Congress, the lead party in India’s ruling coalition, will not risk losing Hindu voters by acting against the RSS or its affiliates. John Dayal, president of the AICU, said: “The Congress cannot afford to antagonise the Hindu majority. Christians do not matter. They are not a vote bank.” For its part, the RSS denies involvement in the Orissa unrest. Asked about the nun who claims to have been raped, a senior Bajrang Dal spokesmen suggested that the sex must have been consensual.

What cannot be in doubt, however, is that the incendiary rhetoric adopted by the VHP did nothing to calm the crisis. The trigger for the violence was the murder of Lakhmananda Saraswati, an extremist VHP leader who had campaigned against the alleged conversion of Hindus to Christianity in the state for 50 years.

Maoist rebels claimed responsibility for the killing, but the VHP hierarchy blamed Christians for Lakhmananda’s murder and pledged vengeance. “Christians have killed Swamiji,” Gouri Prasad Rath, the general secretary of the VHP in Orissa, said immediately after the murder. “We will give a fitting reply.”

Hours later trees were being felled across Kandhamal’s roads to stop the police from getting in and Christians from escaping.