India Deploys Hundreds of Security Forces in Uttar Pradesh NEW DELHI - India deployed thousands of police officers and army troops to a region in the north of the country on Monday after weekend confrontations between Hindus and Muslims that killed at least 28 people and gravely injured many more, according to the police. Widespread clashes were set off by the killing of two Hindu youths on Aug. 27 near the city of Muzaffarnagar, about 80 miles north of New Delhi, in the state of Uttar Pradesh. Officials say the explosion of violence was fed by a video clip that circulated on the Internet and through social media last week, purportedly showing the lynching of the two young men. The clip was "very provocative and spread like wildfire," but was not authentic, having been shot several years ago on the border with Afghanistan, Kaushal Raj Sharma, a top official from Muzaffarnagar, said in an interview. Some 5,000 farmers gathered on Saturday to demand action in the killings, and when the police ordered them to disperse and return to their homes, they "indulged in violence," killing 13 people, Mr. Sharma said. Over the next two days, groups began fighting with knives, sticks, bricks, stones, swords and iron rods, and the fighting spread to nearby villages. As of Monday afternoon, just over half of the people killed were Muslims, Mr. Sharma said. Dozens of Muslim families were seen leaving the area on Sunday night, their possessions piled onto carts drawn by horses and bullocks. Refugees spoke of roving groups of armed men who would attack whole families, including children. Mohammed Haneef said a group of his children and relatives had spent 24 hours hiding in fields, and were hoping to continue on under police escort. "We don't feel safe in this village, where we form less than 10 percent of the population," he told The Indian Express, a daily newspaper. A local broadcast journalist was shot in the chest while filming the violence, according to a report from his station, IBN. A police photographer was also killed. The police have arrested 90 people, Arun Kumar, the state's deputy police chief, said on Monday. Thousands of security forces have been deployed in the area, including some 2,500 riot police officers and roughly 800 soldiers, Mr. Sharma said. Among India's 29 states, Uttar Pradesh has had the highest number of deaths from religious violence in the past three years - 73 killed in 323 outbreaks, according to government statistics. Two thousand such episodes were recorded throughout the country during that period. One of the worst outbreaks took place in 1992, after a Hindu crowd stormed a mosque - which many contend was built on the site of a Hindu temple - and demolished it with sledgehammers and their bare hands. Thousands of people, most of them Muslims, were killed in that outbreak. The new episode is likely to revive discussion of the Internet's role in setting off mass violence. Fake video clips and doctored photographs - easily downloaded on smartphones, now pervasive even in rural areas - were cited as a cause for a panic that set off a riot and caused tens of thousands of migrants to return to their homes in northeast India last year. People received images purporting to show Muslims killed by mobs in India. Officials said they actually showed victims of natural disasters. In the wake of that, the Indian government embarked on an uneven crackdown on the Internet and text messaging services, blocking about 250 Web pages and seeking to block the Twitter accounts of a number of journalists and commentators. Mr. Sharma, the Muzaffarnagar official, said the clip was published and identified as footage of the Aug. 27 episode by a member of the State Parliament representing the Bharatiya Janata Party, or B.J.P., India's main opposition party. He said the police had charged six politicians, four of them associated with the B.J.P., with inciting violence, through inflammatory speeches and the circulation of the video clips. Ravi Shankar Prasad, one of the B.J.P.'s leaders, said local officials had prevented him from traveling to the scene of the violence on Monday to investigate, but he dismissed the charges against B.J.P. officials. "The administration is trying to implicate them to hide their own incompetence," he said.