An attack on King Khalid International Airport in Riyadh has killed 12 people and injured more than 300 others, making it the deadliest attack in any Gulf Arab state since the outbreak of the Iran war.

Saudi civil aviation authorities said several of the injured remain in critical condition and are receiving treatment at multiple hospitals across the capital.

The fatalities included four Saudi nationals, two Bangladeshi citizens, and one citizen each from Palestine, the United States, Egypt, Jordan, Syria and Sudan.

The strike is the latest in a series of attacks targeting Riyadh’s main international airport over the past week and is expected to intensify Saudi efforts to secure greater military backing from allies, particularly the United States.

Shortly after the attack, U.S. President Donald Trump said Washington was assessing whether it should join Saudi military operations against the Iran-backed Houthi movement in neighbouring Yemen.

“We may. We’re going to look at it,” Trump said, adding that the administration had only recently received details of the attack and would make a rapid decision.

According to regional officials, a missile struck a section of the airport complex housing Terminals 3 and 4, which primarily serve domestic flights.

The Houthis had previously claimed responsibility for earlier attacks on King Khalid International Airport this week that killed three Saudis, including a pilot. There was no immediate claim of responsibility for Saturday’s strike.

The incident comes amid a sharp escalation in fighting between the Houthis and Saudi-backed Yemeni government forces after a Saudi-led coalition launched a major offensive aimed at reversing recent Houthi territorial gains.

The rebels earlier accused Saudi Arabia of carrying out strikes on Sanaa International Airport in Yemen’s Houthi-controlled capital.

Saudi authorities temporarily suspended operations at Riyadh airport while emergency teams assessed the extent of casualties and damage. An official notice to aviators stated that the closure would remain in place until midnight.

Security around the airport was significantly reinforced, with police sealing access points and reducing lighting levels throughout parts of the complex.

Flight-tracking data showed aircraft being diverted to alternative destinations, while several governments, including the United States, Britain, Germany, Australia and Canada, advised their citizens to avoid the airport.

The attack has renewed concerns over regional security and the vulnerability of critical infrastructure in Saudi Arabia, the world’s largest oil exporter. Despite the disruption, Saudi officials continued preparations for a major international energy conference scheduled to begin in Riyadh.

Military and energy markets are closely monitoring developments, particularly given the growing threat to transport and energy networks across the Gulf region.

Fighting in Yemen has intensified along the Red Sea coast, where Houthi advances have improved the group’s ability to monitor maritime traffic moving through one of the world’s most strategically important shipping corridors.

That route has gained even greater significance as Iran continues hostile actions against vessels operating near the Strait of Hormuz, increasing concerns about wider disruptions to global trade and energy flows.

While the Houthis maintain that their maritime campaign is directed only at Saudi shipping and forms part of a retaliatory blockade, international observers remain concerned that attacks could widen further.

The group previously targeted commercial shipping following the outbreak of the Gaza conflict, claiming solidarity with Palestinians, although earlier U.S. military operations substantially reduced its operational capacity.

Regional officials have indicated that Saudi Arabia is facing shortages of missile interceptors and has sought additional air-defence assistance from France, Britain, Pakistan and Egypt.

Officials have also said the United States has provided intelligence sharing, target identification and operational planning support for the current Saudi-led offensive against the Houthis.

Saudi Arabia’s Foreign Minister and his Omani counterpart held discussions on Saturday regarding efforts to support diplomatic solutions and reduce tensions across the region.

Oman, which sits across the Strait of Hormuz from Iran, has frequently acted as a mediator during regional crises and remains one of the few channels for dialogue between competing actors.

Meanwhile, Saudi authorities have warned members of the public that filming, publishing or distributing information related to missile interceptions, drone attacks or impact sites could expose individuals to legal penalties.

The latest attack highlights the increasingly regional nature of the conflict, with the Yemen front now emerging as one of the most dangerous and strategically sensitive theatres linked to the wider Iran war. Recent reports indicate that repeated attacks on Saudi airports, oil facilities and military sites have exposed strains on the kingdom’s air-defence network, raising the prospect of greater international involvement should the security situation continue to deteriorate.

Agencies