The incident occurred when the victim Wazir, a resident of Patna, had gone to a nearby shop and two youths indulged in an altercation with him over a petty issue, police said.
The accused had allegedly started beating him black and blue, injuring him fatally, sources said.
Police said the accused have been identified and would be arrested soon.
Wazir was working as a daily wager in the private firm, sources said.