Two men from the girl's village in Uttar Pradesh state were arrested on suspicion of murder after she was found strangled to death in a field, according to police. Additional charges of rape and gang rape were added following a postmortem.
India's caste system was officially abolished in 1950, but the 2,000-year-old social hierarchy imposed on people by birth still exists in many aspects of life. The caste system categorizes Hindus at birth, defining their place in society, what jobs they can do and who they can marry.
A case under the Scheduled Caste and Scheduled Tribe (Prevention of Atrocities) Act has also been filed against the two arrested men, the police said.
The girl left home in Pakaria village in the Lakhimpur Kheri district on Friday afternoon for a toilet break in the nearby fields, said Sandeep Kumar, a junior officer with the Uttar Pradesh police.
When she did not return, her family began searching for her and found her body in a sugarcane field, Kumar said.
A post-mortem examination found the girl was raped and died of strangulation, according to Kumar. He denied her body was mutilated in any way as claimed in some local media reports.
Kumar declined to comment if the crimes were committed against the girl because she was a Dalit. He said an investigation is still underway.
Chandrashekhar Azad, a Dalit rights activist, said oppression against Dalits is "at a peak" under the government of Prime Minister Narendra Modi's Bharatiya Janata Party.
"Our daughters are not safe, our homes are not safe, there is an atmosphere of fear all around us," Azad tweeted on Saturday.
A pervasive problem
News of the girl's death stirred fresh public anger in India, which has been grappling with the pervasive problem of sexual violence against women.
According to India's National Crime Records Bureau, more than 33,000 cases of alleged rape were reported in the latest available figures from 2018 -- roughly 91 cases each day. But experts say that the real number is likely much higher, owing to the shame attached to sexual assault and the social barriers faced by victims.
"The ruthless killing and rape of a girl in Lakhimpur Kheri is an incident which has shaken humanity," tweeted Akhilesh Yadav, the former chief minister of Uttar Pradesh and a member of the opposition Samajwadi party, on Sunday.
In India, sexual assault has in the past been seen by authorities as more of a social and cultural issue rather than a concern for law enforcement, according to women's rights activists, with existing laws failing to protect women.
Unlike previous high-profile rape cases, the girl's murder has not drawn street protests, partly due to the Covid-19 outbreak raging across India, which has seen more than 2.6 million cases of the disease.
Additional legislation was passed in 2018 following the heavily publicized rape and murder of an 8-year-old girl. The amended law lengthened prison terms and introduced the death penalty in cases where the victim is younger than 12 years of age.
However, many of the problems associated with India's rape crisis continue and high-profile rape cases have continued to hit headlines.
CNN's Julia Hollingsworth contributed reporting.