TANK: (AM News) Four members of a family were killed in firing and a hand grenade attack on a house in village Kot Khadak here on Saturday night, Dunya News reported. According to police, unidentified assailants hurled a hand grenade at the house of one Salahuddin before resorting to firing. As a result, Salahuddin, his two sons and a nephew were killed. The unidentified attackers escaped after killing the four members of a family. Having being informed, a heavy contingent of police reached the crime scene and started a probe into the quadruple murder after shifting the dead bodies to Tank DHQ Hospital for autopsy. Police said the murder of the four people could be the outcome of old enmity, adding a thorough investigation into the incident will ascertain the reason for the killing.