The four accused persons have been apprehended, police said, adding that the adult accused have been identified as Deepak, who was previously involved in burglary cases, and Ravi.
The victim, identified as Rahul, was walking past a market in the Rohini Sector 20 area on Thursday evening when he saw a group of persons engaged in a brawl over some dispute related to Holi celebrations.
Deciding to intervene, he entered into an argument with some youths in the group, a police official said.
The accused had fled the scene by the time locals gathered there, police said, adding that Rahul was rushed to a hospital where he was declared dead. The victim had sustained multiple stab injuries.
A case of murder has been registered in this connection at Begumpur police station, the official said.
During interrogation, it emerged that all accused were in an inebriated state when the incident took place. It also turned out there was personal enmity between Rahul and Deepak, which has prompted investigators to suspect that the entire incident could have be premeditated, the official added.