The girls' parents were out of town when the incident occured.
In a village in Bihar's Katoria in Banka district, three minor sisters were found murdered at their house on Tuesday morning. The police said that there were cut marks on their throats and sharp-edged weapons were recovered from the crime scene. They also suspect that the girls were raped before they were murdered.
The family was poor and since no items were stolen from the house, rape cannot be ruled out, said police.
The girls were alone at home when the incident occurred as their parents had gone out of town.
The police has arrested two men in the case and has sent the bodies of the sisters for post-mortem.
"A post-mortem report and forensic analysis will help shed more light in the case," a police official said.
(With Inputs From ANI)