Balasore, Jan. 28: Four persons, including three members of a family, were killed while in their sleep at Paganai, a tribal hamlet in Balasore Sadar police limits, early this morning. Police suspect family dispute behind the murders that has sent shockwaves across the district.

The deceased have been identified as Prativa Mandal, 40, her daughter Suman Mandal, 19, son Subali Mandal, 17, and nephew Bibek Majhi, 13.

Police sources said eight to 10 assailants came on five motorcycles and hacked them to death. They fled the spot under the cover of darkness. The police have seized an empty cartridge, a sword, a chopper and a lathi from the place.

The murders came to light this morning when villagers saw the severed head of Prativa lying 200 metres from her house. Suman was pursuing a diploma course, while Subali and Bibek were students of classes IX and VI respectively.

Balasore police superintendent Niti Sekhar said: "The incident is the fallout of a family dispute. The accused persons have been identified and efforts are on to nab them. We have formed three squads to nab the culprits."

The police rushed a forensic team and a dog squad to the spot. "We have seized an empty cartridge from the spot," said sub-divisional police officer Amaresh Panda.

The police have registered a case under sections 302 (murder), 201 (causing disappearance of evidence of offence or giving false information to screen offender), 34 (criminal act done by several persons with common intention) of the Indian Penal Code and sections 25 and 27 of the Arms Act against the assailants.

The bodies have been sent to the district headquarters hospital for autopsy. Villagers told the police that they had seen the some suspicious-looking motorcycle-borne people in the area last evening and also heard the sound of a shot being fired late at night.

Prativa's husband Satyaranjan Mandal works as a daily wage labourer in Chennai. Anita Majhi, the mother of Bibek, said: "Family members and cousins have committed the heinous crime with the help of some others."

Anita Majhi linked the killings with the sensational murder of Mahesh Majhi at Motiganj in Town police station limits on October 27 last year. Majhi had been killed in his asleep and some of his family members had also been injured in the incident. The police had arrested Kharavela Majhi, the cousin of Mahesh and brother of Prativa, in connection with the murder, along with three others.

"Since Prativa is the sister of Kharavela Majhi, who is currently lodged in Balasore jail, the assailants appear to have attacked Prativa and her two children out of revenge. Bibek, the son of Anita Majhi and nephew of Prativa, also fell victim as he was present in the house at the time of attack," said a police officer probing the case.