Three men suspected of gang-raping an elderly Indian nun at a convent have been pictured for the first time. The woman, who is in her 70s, was trying to prevent  the men from robbing the Christian missionary school when she was attacked. CCTV has now been released showing the suspects leaving the staff room on Friday night. A reward of 100,000 rupees (around £1,075) is on offer for any leads, police said. Five others have been detained for questioning about the attack at the Convent of Jesus and Mary School in West Bengal. Scroll down for video . Three men suspected of gang-raping an elderly Indian nun at the Convent of Jesus and Mary School in West Bengal have been pictured for the first time . Arnab Ghosh, a police superintendent, said: 'CCTV footage showed that six men, aged between 20 and 30, scaled the boundary wall around 11.40pm and entered the school and disconnected the telephone lines.' The robbers then tied up and gagged a security guard before entering the nuns' room, where they found the women sleeping, police said. When the victim, who is the oldest nun at the school, tried to stop them taking another woman into a separate room they raped her. The men escaped with some cash, a mobile phone, a laptop computer and a camera. They also ransacked the school's chapel and took holy items. Footage shows books and papers strewn across the floor as the men leave the staff room. The CCTV footage has  been released showing the suspects leaving the school's staff room around midnight on Friday. Five other men have been detained for questioning . The robbers  tied up and gagged a security guard before entering the nuns' room. Furious residents and students took to the streets after the attack to demand justice . Nuns gather in front of the convent. Archbishop Thomas D'Souza said the sisters prayed for the victim during Sunday Mass . Mr Ghosh added: 'At least two of them were armed and the rest were carrying burglary tools. In the chapel, a holy scripture was found torn and a bust of Jesus was broken.' The nun is recovering in hospital in Ranaghat. Furious  residents took to the streets yesterday, shouting slogans demanding action and blocking off the main highway. Mamata Banerjee, West Bengal Chief Minister, also tweeted her condemnation of what she called a 'horrific attack', promising 'swift, strong action'. The nun is recovering in hospital in Ranaghat. Meanwhile hundreds of people blocked off the main highway holding signs and candles . Others sat on a patch of grass with a sign made from a broken stick, cardboard and paper. 'We want justice' was written in red pencil . Teenagers and students lit dozens of white and yellow candles at the peaceful protest yesterday . The students from the convent, dressed in a smart red and white uniform, each held a white candle by hand . Archbishop Thomas D'Souza has appealed to people to maintain peace and harmony in the area. He said: 'In our Sunday Mass, we prayed for the sister to recover quickly from trauma, fear and her physical injuries. We will pray for her again this evening. 'They not only committed a heinous crime, but they also vandalized the chapel. This is the first time such an attack has happened in India.' Five nuns wait outside the convent while police are on scene. The incident comes at a time of heightened sensitivity over women's safety in India . Seven police officers stand guard at the convent while others comb the area for evidence and ensure the nuns are safe . The incident comes at a time of heightened sensitivity over women's safety in India, which last week saw  a documentary about the 2012 gang-rape of a student in Delhi being banned. Authorities said screening the documentary could have caused public disorder, but critics accused the government of being more concerned with the country's reputation than the safety of its women. Shocking footage also emerged this week of an angry mob stripping and slowly beating a man to death in an Indian village after he was accused of raping and murdering an 11-year-old girl. The prolonged attack on the 18-year-old was watched by a jeering 1,000-strong crowd.
Nun was trying to prevent six men from robbing the Christian school . Gang believed to have gagged security guard before violent rampage . CCTV footage released shows suspects leaving the school's staff room . Five others have been detained for questioning, police said . Latest in a series of violent gang-rapes that has shocked the country .