New Delhi, Sep 22 (PTI) An 18-year-old man was arrested and three juveniles were apprehended after they allegedly stabbed three people, killing one of them, in northwest Delhi’s Mangolpuri area, police said on Wednesday.According to the police, they found Yashish (22) and Raj Kumar (42), both residents of Mangolpuri, with stab wounds on Sunday and took them to the Sanjay Gandhi Hospital.Another Mangolpuri resident, Mihir (18), was found admitted with stab injuries too, a senior police officer said.Yashish told the police that that he was sitting outside his house when around four people tried to snatch his mobile phone. When he resisted, he was stabbed by one of them, the officer said.Meanwhile, his neighbour, Raj Kumar, tried to intervene, and he was also stabbed. The accused then escaped from the spot, the police said.They had a scuffle with Mihir at a nearby place and stabbed him too, the officer said.Two separate cases under relevant sections were registered at the Mangolpuri police station, and an investigation was taken up, the police said.During the investigation, all four accused were apprehended. Out of them, three were juveniles. The knife used in the crime was recovered at their instance, Deputy Commissioner of Police (outer) Parvinder Singh said.The accused revealed that Yashish had beaten one of their associates, and hence they took revenge. They also said that Mihir, along with his associates, wanted to assault them, and that is why they stabbed him, the DCP said.Kumar succumbed to injuries on Wednesday morning at the Jaipur Golden Hospital, and section 302 (murder) has been added in the FIR. PTI NIT IJT