Bhagalpur: Three sisters were found murdered in Banka district on Tuesday morning, and police suspect the girls aged between seven and 16 years were raped.

The girls were alone at home in a village under the Katoria police station in Banka, around 320 km southeast of Patna. The girls' father works as a daily wage labourer in Bengal, and their mother had gone to Jharkhand. When she returned home on Tuesday morning and found the house locked from outside, the mother raised an alarm. Neighbours broke open the room to find the girls' bodies.

Banka superintendent of police (SP) Chandan Kushwaha said the bodies were in semi-nude condition, which indicated that they were raped before they were killed with sharp-edged weapons. Marks of external injuries were also found on the girls, he added.

Two persons have been detained for interrogation.

Local residents told the police that the eldest sister was a school dropout, the second one was studying in Class IX in a local government school. The third sister was not enrolled to any school.

SP Kushwaha said that a forensic team visited the spot and collected evidences. A special investigation team headed by a deputy superintendent of police Binod Kumar Gupta has been formed to crack the case at the earliest.

The girls' mother has named a few suspects, police sources said.

Kushwaha said that an axe and another sharp-edged weapon are suspected to have been used in the murders as blood-stained clothes have been recovered from the spot. The bodies bore cut marks around the neck and forehead. The post-mortem has not revealed whether the girls were sexually assaulted, he added.