A missile strike on King Khalid International Airport in Riyadh killed at least 12 people and injured 309 on Saturday, Saudi civil aviation authorities said. Some of the wounded were in critical condition, and airport operations remained suspended Sunday.

The dead included one American, four Saudi citizens and people from Bangladesh, Egypt, Jordan, Palestine, Syria and Sudan. Saudi Arabia, its allies and Washington blamed the Houthis, but the group had not immediately claimed responsibility. It renewed a warning to avoid Saudi airports.

President Donald Trump said Saturday that the United States was considering joining Saudi military operations against the Houthis. The strike followed another attack at the airport on Thursday that killed three people, amid renewed fighting between the Yemen-based group and a Saudi-led coalition.