The beating and subsequent death in New Delhi of a university student from India's remote northeast has sparked a furious outcry against racism and criticism of police.
Several hundred people protested outside a Delhi police station Saturday, shouting demands for justice against what they called a hate crime.
The capital's newly elected chief minister asked that a magistrate investigate the incident as well as the police response.
Police detained two shopkeepers and launched a murder investigation Friday night, after being criticized for doing little following Wednesday's altercation.
"We are questioning several people in the case," said Delhi police spokesman Rajan Bhagat.
Officials said 20-year-old Nido Tania had been on vacation from his studies in Jalandhar, Punjab, when he was beaten by New Delhi shopkeepers who had ridiculed his appearance.
Many indigenous people from India's northeast, some ethnically closer to people in Myanmar and China, often say they encounter racism and discrimination in the rest of India.
Tania died in his bed on Thursday morning. An autopsy was being conducted to determine a cause of death.
Tania was the son of a member of the Arunachal Pradesh state assembly from the nationally ruling Congress Party. The Home Ministry also asked police for a detailed report.
Hundreds of students held demonstrations in front of a police station and near the shop where Tania was beaten in the south Delhi neighborhood of Lajpat Nagar.
They carried placards with slogans including "Hang the culprits," and "Why are we treated like outsiders?"
"This was a racist hate crime," said Albina Subba, an advertising writer originally from the northeast Himalayan town of Darjeeling.
"Our community is often targeted like this. ... We look different, so it's easy for people to see we're not from Delhi."
She added: "We have little faith in the Delhi police, but this time we want them to take action."
A Facebook page titled "Justice for Nido Tania" had received support from more than 19,000 people by early Sunday morning (NZT).
"There is no place for elements trying to spread hatred against people belonging to any particular part of the country," Delhi's Chief Minister Arvind Kejriwal said in a statement.
Kejriwal's upstart Aam Aadmi Party, or Common Man's Party, said that the brazenness of the public beating proved that the city's law enforcement was failing its citizens.
The party has been lambasting Delhi police force, which reports to the federal government, since almost immediately after last month's election victory.