Ranjeet Pandey (60) and his two sons, Manoj (35) and Vinod (32), were shot dead when they objected to unloading cattle from a truck in front of their house in Jaitpur cattle market in Sahjanwa area.
Rana Singh, Mukund Singh, Brijendra Singh and Om Prakash have been identified as the main suspects, police said, adding that all four are absconding.