The death of an 18-year-old Dalit youth, allegedly assaulted over an inter-caste relationship, triggered protests in Uttarakhand's Tehri Garhwal district on Tuesday, with villagers and family members demanding the arrest of all those involved in the attack.

The victim, identified as Ketan Lal, succumbed to his injuries at Baurari District Hospital, where angry residents gathered and staged a demonstration. His family refused to accept the body for the last rites until all the accused were arrested.

The Uttarakhand government announced compensation of Rs 8.25 lakh for the victim's family.

According to police, Ketan had been in contact with a girl from Kholgarh village in Pratapgarh block for the past six months.

Police said that around 11 pm on Sunday, the girl called Ketan and asked him to come to the village. Ketan travelled there with a friend, Diwakar Dimri.

After they arrived, members of the girl's family allegedly confined the two in a room and assaulted them with sticks, police said. Ketan later died during treatment.

The police have arrested two primary suspects — the girl's father, Yashveer Singh, and her grandfather, Vidya Singh.

Ketan's family alleged that he was subjected to severe torture during the assault. His father, Dhanpal Lal, claimed the attackers used pliers to pull out his fingernails and toenails, drove nails into his feet and inflicted serious injuries to his genitals.

The family also alleged that the teenager suffered extensive injuries across his body.

"I will not take the body from here until all the culprits are arrested, even if it takes four days or ten days," Dhanpal Lal told reporters. "I am a poor man. I do not have the resources to run around courts for years. I want justice delivered right here. Only then will I take my son's body."

He claimed a video of the assault had surfaced on social media and was being circulated locally.

Police said Ketan belonged to a Scheduled Caste community and had been in a relationship with the minor daughter of Yashveer Singh.

On Tuesday, villagers submitted a memorandum addressed to the chief minister through Ghansali Sub-Divisional Magistrate Manju Rajput, demanding a fair investigation, justice for the victim and security for his family.

Tehri Senior Superintendent of Police Shweta Choubey said an intensive investigation was underway and assured that all those involved would be brought to justice.

Police and forensic teams have inspected the crime scene and collected evidence, she said.

Chief Medical Superintendent Dr Amit Rai said the post-mortem report was expected within two days.