A Dalit man, identified as Harendra Kumar, was thrashed in his private parts and a rod was allegedly inserted into his rectum by the attackers.
The 22-year-old man was attacked and abused by the family of a girl from a higher caste who thought the two were in a relationship, reported The Times Of India.
The incident took place after midnight on Wednesday at Tikunia town in Uttar Pradesh's Lakhimpur Kheri district.
Harendra is now fighting for his life at a district hospital.
"On Wednesday, Harendra had woken up before dawn and gone to an orchard. Brahmdeen (the girl's father) and his three sons- Raju, Bharat and Gajraj attacked him, abused him for being a lower caste. They thrashed him with an iron rod, baton and belts. Then, they inserted an iron rod into his rectum and repeatedly thrashed him in the private parts with the rod," Harendra's cousin Anuj said.
"Here, even a friendship is considered wrong. My brother was focused on his career and had decided to get married only after he cleared the exams," he said.
The police said that Harendra was involved with the girl and was attacked by her family when he was trying to meet her.
"The accused said Harendra was trying to enter their house and steal something. We found out it was a lie," SHO of Tikunia police station Gyaan Singh said.
Meanwhile, the accused-Brahmdeen, Raju, Bharat and Gajraj were booked under the SC/ST act and for voluntarily causing hurt and intentional insult.
The three of them have been arrested, the police said, adding that a sector for heinous crime will be added after the supplementary medical examination.
"He has injuries on almost all parts of the body, including his private parts. He was beaten up with a baton and bare hands. The injuries to his face were life-threatening, but he has responded to the treatment," the police said.