The attack on the Saudi city of Najran came after Iran announced it has quadrupled its uranium-enrichment production capacity, though still at a level far lower than needed for atomic weapons.
In December, about 30 Iranian Revolutionary Guard vessels trailed the aircraft carrier John C. Stennis and its strike group through the strait as Associated Press journalists on board watched.
Iraqi officials said ExxonMobil Corp. began evacuating staff from Basra, and Bahrain ordered its citizens out of Iraq and Iran over "the recent escalations and threats."