A 50-year-old operator with Uttar Pradesh Jal Nigam and three of his family members were bludgeoned to death by unidentified assailants in his house near Chandapur village in Varanasi Tuesday night. Police said the incident occurred at 9.30 pm when Mohan Lal,his wife Dhuni,45; sons Sandeep,20, and Pradeep,18; daughters Pooja,25, and Arti ,22,were present in the house. The assailants reportedly first attacked Mohan Lal with an iron rod and then attacked Dhuni,Sandeep,Pradeep and Pooja when they tried to save him. The injured were rushed to Deen Dayal government hospital,where Mohan Lal,Dhuni,Pradeep and Pooja were declared dead on arrival. Police suspect property-related dispute or a personal grudge as reasons for the attack.