In a case of honour killing, a Dalit youth in Bijnor district of Uttar Pradesh was killed by the family of an upper caste girl with whom he was in a relationship, police said on Friday.

The girl's father Madan, two brothers and an uncle have been booked for killing the 21-year-old Atul Kumar, whose body was found on Thursday on the outskirts of Dehlalawala village, police said.