Mehtab Ali and Rahul Thakur, a Muslim and a Hindu both 23, lived in adjacent streets. Both died this week in Delhi's worst religious riots in decades. As the accounts of family and friends of the two young men make clear, who or what sparked the several days of violence that left 42 people dead remains unclear. Both lived in Hindu-majority Brijpuri, a district adjoining the Muslim-dominated Mustafabad, both part of the Indian capital's northeastern fringe that was the epicentre. The area is a nondescript low-rise warren of narrow streets, shops and places of worship that are home to people who for generations have rubbed along together. Today it resembles a warzone, littered with rocks, broken glass from Molotov cocktails, bullet casings and the charred remains of homes, shops, schools and vehicles. - Rahul's death - Thakur was known as a quiet boy who used to teach children while himself preparing for competitive government examinations. He is survived by an elder brother and their parents. "He was one of the friendliest and most studious young men in the locality with a promising life ahead of him," Nitin Sharma, his close friend and neighbour, told AFP. According to Priyadarshan Suryavanshi, another neighbour, trouble started on Tuesday when people taking part in a nearby demonstration tried to block the road. The sit-in protest was one of many to spring up in recent weeks over a new citizenship law that many Muslims worry is a first step to their marginalisation -- or worse. "When (the protestors) became aggressive, there was a pushback from those opposed to shutting roads and businesses. It soon spiralled out of control into a Hindu versus Muslim issue," Kapil Pandit, another resident, told AFP. Locals said a large Muslim mob from Mustafabad, which is across a small bridge over a narrow drain from Brijpuri, started pouring in and throwing stones. "It was chaotic and loud, and we rushed out from our homes to see what was happening," said Sharma, who was with Rahul at the time. "We hadn't even clearly understood what was happening when a bullet fired from the mob on the other side hit him. He cried out 'oh brother' and collapsed. We rushed him to a hospital but he couldn't be saved," Sharma added. The locals complained that the police took for ever to respond to their desperate calls for help. "Most of the young men on the road were using sticks and stones to stop that murderous mob armed with guns, petrol bombs, knives and oil from getting to our homes, families and businesses," Dipin Kumar, a local shop owner, said. "It was a crazy, violent mob chanting religious slogans. "I kept calling (the police) for hours and by the time they arrived, the Muslim mob had already burnt a school, looted some shops and done too much damage," Kumar added. "Thank God they arrived. We'd be dead otherwise." - Mehtab's death - Mehtab's home 100 metres (yards) away is similar to Thakur's, but the stories residents tell are different. "All this was started by them," one of Mehtab's three elder brothers said, referring to the Hindus in the neighbourhood. "They intentionally approached the ongoing peaceful sit-in protest with very provocative sloganeering on Tuesday," he told AFP outside their family home. "The matter escalated as more people came there to back the protestors from Mustafabad, across the small bridge on the drain," he added. His Muslim neighbours said that soon many more people joined the Hindu group, which became ever more aggressive and suddenly started attacking the protestors, sparking panic. Mehtab's mother Khusnoodi said her son got back home just when the chaos started "but left again as he wanted to fetch milk to have some tea". That was the last time the family saw him alive. They were informed later that evening that he had died and was at one of the local hospitals.