The incident which took place last night was triggered by a row over one man allegedly urinating before a house belonging to another man Allauddin in Pant Nagar locality under Chanda police station area two days ago, Superintendent of Police, Vinay Kumar Yadav said.
The accused, identified as Laeeq, attacked the member of the house with sharp-edged weapon, he said.
While Allauddin's sons Jauhar (18), Gauhar (16), and his nephew Javed (20) died on the spot, two other members of his family, including a woman were seriously injured and rushed to Trauma Centre in Lucknow, Yadav said.