At least four explosions rocked Gaza City early Sunday, targeting cars belonging to officials from Islamic factions, including the territory’s Hamas rulers. There was no claim of responsibility, but speculation immediately centered on supporters of the Islamic State group who have been battling with Hamas and other Islamic groups in the small coastal strip. Hamas recently launched a fierce crackdown on alleged IS supporters and witnesses said a freshly painted Islamic State group flag was seen at the site of the explosions. The charred vehicles were parked outside the houses of the local officials in the Sheikh Radwan neighborhood of Gaza City. Khader Mahmoud, a 32-year-old witness, said the blasts occurred seconds apart from each other, just after 6 a.m.