Crude oil surged after CNN reported that US intelligence suggests Israel is preparing for a potential strike on Iran’s nuclear facilities. It wasn’t clear whether Israeli leaders have made a final decision on carrying out the action, CNN said, citing unnamed officials.

Oil has been volatile since last week on mixed headlines about the fate of Iran-US nuclear talks, which could pave the way for more barrels to return to a market that’s expected to be oversupplied later in the year. An attack by Israel would hinder any progress in those negotiations and add to unrest in the Middle East, which supplies about a third of the world’s crude. The CNN report also briefly pushed traditional currency havens including the Swiss franc and Japanese yen higher, before the move pared.