A missile strike on King Khalid international airport in Riyadh killed at least 12 people and wounded 309 others on Saturday, prompting Saudi Arabia to vow a firm retaliation. The General Authority of Civil Aviation suspended all airport operations, canceled or diverted flights, and ordered schools across the capital to switch to remote learning for a week.

The victims included four Saudi nationals, two Bangladeshis, and one citizen each from the United States, Egypt, Jordan, Syria, Palestine, and Sudan. The strike marks the deadliest attack on Saudi soil in over a decade. US Secretary of State Marco Rubio confirmed the American death and condemned the strike. “These reprehensible attacks demonstrate a blatant disregard for innocent civilian life. They must stop now,” Rubio said. The United Nations, Canada, and Germany also issued strong condemnations and travel warnings.

The Saudi-led military coalition blamed Yemen’s Iran-backed Houthi group for the strike, calling it a full-fledged war crime. The Houthis have not claimed responsibility for the airport attack but issued a separate warning on Sunday, telling airlines and travelers to avoid Saudi airspace and stating that Riyadh bears responsibility for any failed interceptions.

Violence has spread across multiple Saudi cities since the attack. A projectile fell near King Fahd international airport in Dammam on Saturday. Attacks on airports in Jizan and Najran wounded three people on Monday, while strikes on Abha and Riyadh on Tuesday killed three more and injured 36. The Houthis also claimed to have set fire to an Aramco oil refinery in Rabigh, though Saudi authorities have not confirmed that damage.

The airport strikes come as ground fighting intensifies in Yemen. Saudi-backed government forces launched the Dawn of Yemen offensive on October 4 to retake Houthi-held territory. Government spokespersons claim they have pushed back rebels near the port city of Mocha and tightened their grip on Taiz, though the Houthis dispute those territorial gains. Experts note the rebels are using cross-border attacks to pressure Saudi Arabia while mobilizing fighters across densely populated areas in southern Yemen.

International allies are moving quickly to support Riyadh. On October 5, Saudi Arabia, Pakistan, and Turkiye agreed to activate deterrence measures under a mutual defense pact to deploy forces to the Gulf kingdom. US President Donald Trump called the strike terrible and left open the possibility of direct US military involvement. “We may. We’re going to look at it,” Trump told reporters on Saturday. Washington has already shared intelligence and planning support for Saudi operations in Yemen, following years of logistical backing that began in March 2015 before the Biden administration ended direct support in 2021.