The killings were a result of one-sided love on part of one of the accused Sonu Harijan with the eldest sister Indu (18), Superintendent of Police Manoj Kumar told reporters.
Bodies of Indu, along with her sisters Priti (9) and Pinky (14), were found with serious head injuries near Katiyari village yesterday, a day after they went missing.
Indu's sisters were killed to destroy evidence, he said.
He said four persons, including Sonu, were involved in the murder. Of the four, Dheeraj Gaur and Amresh alias Loha were arrested this morning and the weapon used in the triple murder recovered.
Sonu Harijan and Raj Kokil, both allegedly involved in the murder, are at large, police said.
Kumar said that post-mortem was conducted by a panel of doctors, including two women experts, which did not confirm rape.
The incident led to demonstration by local residents who demanded Rs 50 lakh as financial assistance to their family.
Chairman of the National Commission for Scheduled Castes PL Punia met the family members of the girls and said he would try that the Uttar Pradesh government extends financial help of at least Rs 10 lakh to them.
He also slammed the state government alleging that there was complete 'jungle raj' in the state.
