A 42-year-old man allegedly killed his mother using a sharp-edged weapon and injured his wife and three children near Ambala city in Punjab, police said on Saturday.
The accused, Harjinder Singh, who worked as a mechanic, fled after the attack, they said.
Singh got into a heated argument over a dispute with his family members on Friday night. In a fit of rage, he attacked his entire family, the police said.
His mother Nayab Kaur (66) sustained serious head injuries and died on the spot. His wife Kulwinder Kaur (40), daughters Anshika (12) and Vanshika (9), and son Jashndeep (6) were also seriously injured and rushed to the civil hospital, they said.
The doctors referred the injured to PGIMER, Chandigarh, due to their serious condition, they added.
A case has been registered against the accused, Shambhu police station in-charge Prem Singh said.