A bomb exploded in a car in Gaza City tonight, killing a Palestinian and one other person, Palestinian witnesses and security sources said.
Members of the al-Aqsa Martyrs Brigade, an armed group linked to Yasser Arafat's Fatah movement, accused Israel of "assassinating" one of their comrades in Palestinian-ruled Gaza.
They identified him as Mr Wael al-Namara and said he was also a member of the Palestinian Preventive Security service. The Israeli army had no immediate comment.
The blast left the car a mangled wreck and sent smoke rising over the area near the Shati refugee camp in the Gaza Strip. A Reuters correspondent at the scene saw the headless, dismembered body of a second victim lying near the car. Hospital officials said they had not been able to identify the body.
The al-Aqsa Martyrs Brigades is one of the man groups behind a wave of suicide attacks and shooting ambushes that have killed scores of Israelis during the 21-month-old Palestinian uprising against Israeli occupation.
Israel has tracked down and killed dozens of militants under an internationally condemned policy it calls self-defence but the Palestinians have branded state-sponsored assassination.