An 18 year old killed his grandparents in a village in Uttar Pradesh's Ballia district after they objected to his smoking in the house on Friday, police said.
The incident took place on Thursday in the Bauara village of Ballia, 300 km from Lucknow.
"Ramdhar and Radhika caught their grandson smoking in the house and raised objections. In a fit of rage, Jugnu killed both of them with a knife," police inspector N.S. Yadav told reporters in Ballia.
"A servant, who was present in the house at the time of the incident, informed us after which we rushed to the spot. By then Jugnu escaped," Yadav said.