The robbers wearing masks barged into 43-year-old Raja's house to commit robbery and when he opposed them, they stabbed him to death, SSP, Yashasvi Yadav said.
The accused also injured Raja's wife Ramakanti (36) and daughter Richa (14) when they tried to save him, Yadav said, adding that they fled without robbing anything.
The victims were rushed to hospital, where Raja was declared dead and the other two are being treated, he said.
However, police suspect that the accused may have been known to the victims and there might have been some ulterior motive behind the crime.