The incident took place yesterday at Devkhari village in Kandharapur area.
The robbers barged into the house of a 60-year-old man and started beating him and his 30-year-old son, while holding other members of the family hostage, they said.
They killed the father-son duo and another family member before decamping with cash and valuables, police said.
A manhunt has been launched for the assailants, they said.
