24-year-old Punit Kumar had fallen in love with a girl belonging to a different caste.
The girl's family members spotted them in an objectionable situation at their house yesterday. Infuriated family members questioned them and later the boy was stabbed to death while the girl was seriously injured, DSP Karmvir Singh said.
The girl was rushed to hospital in serious condition, while the body of boy has been sent for autopsy, he added.