A Gaza man was shot to death Thursday during a showdown between his Fatah-affiliated family and members of Hamas, according to Hamas officials. Samir Hilles, 40, was trying to mediate between Hamas gunmen and members of his family, who blocked the vehicle the militiamen were driving, forced out its six occupants and torched it. Gunfire erupted after militia reinforcements arrived, and Hilles was killed, Hamas said. Although his family is affiliated with Fatah, Hilles was a Hamas supporter, the officials said. "Unfortunately, elements interested in creating an explosive atmosphere are creating new internal tensions," said Ayman Taher of Hamas, a liaison with Fatah in the Gaza Strip. "What happened yesterday and now cannot be justified, and we are calling on our brothers in Fatah to do their utmost to restore calm and end this atmosphere of tension."