Israel is bracing for a direct and unprecedented attack by Iran on government targets as soon as Saturday, according to people familiar with western intelligence assessments, a move that has the potential to trigger an all-out regional war.

An assault from Iranian soil has emerged as one of the main scenarios expected by Israel and its allies, said the people, who asked not to be identified as they aren’t authorized to discuss the matter publicly. A bombardment with drones and precision missiles could come within the next 48 hours, they said.