Hamas gunmen shot and killed a Palestinian motorist on Monday when he refused to stop at a roadblock they had set up in the southern Gaza Strip, witnesses said. Hamas operatives said shots were fired first from the approaching car, and that they fired back. The incident took place near the southern Gaza town of Khan Younis. The identity of the dead man was not immediately known. Earlier, four Palestinians were killed in an IAF airstrike on central Gaza. The four men were standing on a street in the Shajaiyeh neighborhood of Gaza City when a missile hit them, witnesses said. The four were severely burned and dismembered, Palestinian doctors said. The IDF said that troops operating in the area shot and killed the armed Palestinians in an exchange of fire. Elsewhere, IDF troops shot and killed an apparently unarmed Palestinian civilian in the West Bank city of Jenin, the army and witnesses said Monday. Sabri Halil, 64, was shot late Sunday night by troops on patrol in the city. Witnesses said he was a local guard at a school and was shot in the heart after he aimed his flashlight at a passing car. He died on the spot. The army said its forces noticed a man on a rooftop holding what looked like a weapon when they opened fire at him. The army said the man probably was holding a flashlight and it launched in investigation into the incident.