The bodies of the victims, identified as Sujata Kumari (9) and her sister Rajni Kumari (7), were found from a paddy field, police said.
According to an FIR lodged in this connection, the minors had gone to attend a marriage party alongwith a familiar person Abhisekh Kumar last night.
The three accused Basant Prajapati, Rajdeo Kumar and Manoj Kumar intercepted them while returning home but let off Abhisekh.
The victims were strangulated and their bodies were dumped in a paddy field, which was recovered today, police said adding that the bodies have been sent to a local hospital for post-mortem.
Confirming the report, Superintendent of Police Anup T Mathew said the reason behind the killing was not yet ascertained.
The victim's father Ashok Ram has been working as daily wager in Punjab.