Ram Samujh (60), his son Lohar (27), and daughter-in-law Sunita Devi (24), were killed using a sharp edged weapon allegedly by some unidentified persons, police here said.
The bodies were found in their house in Madhukarpur Mahadeva village by neighbours, who informed the police.
A probe is on in the matter, police said, adding that no arrests have been made in this connection so far.