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 Delhis Mangolpuri area police said on WednesdayAccording 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 HospitalAnother Mangolpuri resident Mihir 18 was found admitted with stab injuries too a senior police officer saidYashish 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 saidMeanwhile his neighbour Raj Kumar tried to intervene and he was also stabbed The accused then escaped from the spot the police saidThey had a scuffle with Mihir at a nearby place and stabbed him too the officer saidTwo separate cases under relevant sections were registered at the Mangolpuri police station and an investigation was taken up the police saidDuring 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 saidThe 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 saidKumar succumbed to injuries on Wednesday morning at the Jaipur Golden Hospital and section 302 murder has been added in the FIR PTI NIT IJT