Airlines scrambled to cancel flights into Israel early Saturday after Palestinian militants launched a surprise attack, firing thousands of rockets from Gaza into nearby Israeli towns during a Jewish holiday.

As of Saturday afternoon, about 16% of flights were canceled and 23% were delayed to Ben Gurion International Airport, Israel’s international hub, located just outside of Tel Aviv.

Some Israel-bound flights were diverted to other airports around the globe. United Airlines flight 954 left San Francisco International Airport on Friday night and diverted over Greenland about seven hours into the more than 13-hour-long journey, according to flight tracking site FlightAware. The flight would later return to San Francisco.