Nabil Tammous, a member of a security force loyal to President Mahmoud Abbas, was not there at the time.
The attackers forced their way into the house, blew it up and also seized three bodyguards, security sources said.
The ruling party Hamas, which has clashed frequently with Mr Abbas’s Fatah party, denied any involvement in the attack.
One report said a fourth guard was killed in the incident.
The two factions, Hamas and Fatah, were locked in an intense power struggle for months after Hamas gained control of the Palestinian parliament in elections in January.
Deadly gunfights broke out between members of the rival groups, prompting fears of civil war.
But in June relations improved when the two groups forged a deal on a basis for negotiations with Israel, although it came as the current crisis over a captured Israeli soldier broke out.
The incident came as Palestinians inspected damage in the town of Beit Hanoun in northern Gaza after Israeli forces withdrew.
The Israeli incursion into Beit Hanoun lasted two days
Palestinian health workers said at least six Palestinians had been killed during a two-day incursion which Israel said was aimed at preventing Hamas militants from firing rockets at Israeli territory.
The mayor said Israeli forces had caused damage estimated at $7m to houses, farmland and the electricity and water distribution systems.
Israeli forces have been attacking targets in Gaza for nearly three weeks since Palestinian militants captured Cpl Gilad Shalit.