KANPUR, May 25 -- A violent case of road rage on Sunday night left a father and son dead and another son critically injured after a minor motorcycle collision escalated into a knife attack in Kanpur's Naubasta area, police said. Shivnarayan Trivedi, 60, and his son Shivam, 28, were declared dead on arrival at LLR Hospital while Trivedi's second son Satyam, 30, remains critical. The family, residents of Rampur Kanshiram colony in Sajari, Chakeri, worked at an establishment 'Kanak Marbles' and were riding home after finishing their shift when the incident occurred in front of the Vrindavan guest house on the bypass after their motorcycle brushed against another bike. A heated argument rapidly turned physical as the three attackers began kicking and punching the family. When bystanders tried to intervene, the assailants turned on them, using their helmets to beat back the crowd before drawing knives. According to attending doctors, Shivnarayan and Shivam were stabbed repeatedly in the chest, stomach, and face. Satyam suffered deep knife wounds across his back, hands and abdomen before the attackers fled the scene. The police recovered three motorcycles from the spot. Investigators believe one belonged to the victims, while the other two were abandoned by the attackers. DCP (South) Deependra Nath Chaudhary said the identities of the suspects have been established, and multiple police teams are conducting raids to arrest them. Kanpur police commissioner Raghubir Lal also visited the crime scene late Sunday night. The double murder triggered widespread panic in the neighbourhood, forcing a heavy police deployment to maintain law and order....