New Delhi, April 6 -- A 50-year-old man was killed and at least four people were injured after a continuing animosity between two families living in the same neighbourhood at Shakurpur in northwest Delhi erupted into a clash, police said on Sunday. Three people have been detained in the incident. Police identified the deceased as Rajkumar Gupta, a grocery shop owner. His son, Sumit Gupta (25), and brother, Kishan Gupta (45), were injured in the incident. Two men from the other family - Anand Kishore (in his 50s) and his son Sumit alias Summa (in his mid-20s)- were also injured. Police said Sumit and Kishan Gupta were discharged after medical attention, while Kishore and his son were undergoing treatment and stable. Sumit, Ashish (alias Ashu), and Chetan-all in their 20s - have been detained in connection, said police. The incident took place on Saturday night between neighbours at Sanjay Park in K-Block. The police control room received a call regarding a quarrel at around 9pm. When a team from the Subhash Place police station reached the shop, they learnt that Rajkumar had been stabbed multiple times, said DCP (northwest) Akansha Yadav. "The accused persons allegedly attacked the victims with sticks, rods, and knives. All three were admitted to a nearby hospital, where the shop owner, Rajkumar Gupta, was declared brought dead by the attending doctors," said the DCP. The two sides frequently quarrelled over various issues and the cause behind this particular incident was not immediately clear. Police said they were also probing the exact series of events that had occurred. A first information report (FIR) under Section 103 (punishment for murder) of the Bharatiya Nyaya Sanhita was filed. Locals allegedly told the police that the Kishore's family had recently lodged a police complaint against the Gupta family over, what they said, was "illegal" construction. However, it was not clear if that was the reason behind Saturday night's clash. "It was another reason for the animosity between the two families," said a police officer, who asked not to be named....