Riyadh airport attack kills 12, including an American, and injures hundreds, according to Saudi officials.

CAIRO — The latest attack on the Saudi capital’s international airport killed 12 people and injured more than 300 others, civil aviation authorities said Sunday morning, with some in critical condition.

The attack was the deadliest in any Gulf Arab country since the start of the war in Iran, whose fronts have broadened to include the recent surge in fighting between Iran-backed Houthi rebels in Yemen and Saudi-backed government forces.

The statement, which did not attribute any responsibility for the attack, said the dead included four Saudi citizens as well as two Bangladeshi nationals, a Palestinian, an American citizen, an Egyptian, a Jordanian, a Syrian and a Sudanese. The injured were treated in several hospitals.

The attack – the latest in a series last week on King Khalid International Airport – is expected to increase Saudi pressure on its allies, including the United States, to provide military support to the kingdom.

Shortly after Saturday afternoon’s attack, President Donald Trump said he was evaluating whether the United States should join Saudi strikes against the Houthis.

The Houthis claimed responsibility for attacks earlier in the week on King Khalid International Airport that killed three Saudis, including a pilot..

“We can do it. We’ll think about it,” Trump said of his intervention. “We have just learned of the recent attack. So we will make a decision. We are acting very quickly.”

The surge in attacks, including on other Saudi airports, military installations and oil infrastructure, comes a week after a Saudi-led coalition launched a major military offensive against the Houthis. There was no immediate statement from the rebels, who on Saturday accused Saudi Arabia of striking Sanaa international airport in the Houthi-held Yemeni capital.

Riyadh airport operations suspended

Saudi civil aviation authorities said earlier that airport operations had been suspended and the extent of injuries and damage was being assessed. An official notice to airmen indicated that the suspension would last until midnight. The airport had a heavy police presence, with all entrances blocked and lights around the complex dimmed.

Flights were diverted elsewhere, tracker Flightradar24 said. Countries including the United States, Britain, Germany, Australia and Canada have warned their citizens to avoid the airport.

Attacks on Saudi Arabia, the world’s largest oil exporter, have shaken markets and the region. And yet, hours after the last one, the Saudi Energy Ministry was still promoting a major international energy conference scheduled to open Sunday in Riyadh.

Fighting in Yemen between the Houthis and Saudi-backed Yemeni government forces has intensified, with the Saudi-led coalition providing air support to government forces trying to reverse recent Houthi advances along the Red Sea. The gains allowed rebels to better monitor shipping in a corridor that provides a crucial alternative to the Strait of Hormuz, where Iran attacks shipping.

Although the Houthis have told the AP and others that they are only targeting Saudi ships as part of a blockade in retaliation for one imposed on them, concerns about broader attacks persist. The Houthis had already attacked other ships after the start of the war in Gaza, calling the operation in solidarity with the Palestinians. A US bombing campaign severely limited this.

Saudi Arabia running out of interceptors, officials say

Saudi Arabia is short of missile interceptors and has asked France, Britain, Pakistan and Egypt to deploy air defense support to the region, regional officials told the AP last month, with one noting that the United States has seen its own stockpile dwindle during the war with Iran.

Officials said U.S. assistance included sharing intelligence, identifying targets and planning the latest offensive against the Houthis.

On Saturday, Saudi Arabia said its foreign minister and his Omani counterpart spoke by telephone about the importance of “supporting diplomatic solutions to defuse tensions” in the region. Oman, located across the Strait of Hormuz and Iran, has at times played a mediating role in the region.

Meanwhile, Saudi authorities warned the public this week that “filming, publishing or sharing information related to countering missiles and drones and their impact sites exposes you to legal liability.”

Flight disruptions are increasing

The Houthis this week warned global airlines “for the last time” about the potential consequences of operating in Saudi airspace, which they described as the theater of their military operations.

At least 291 flights at Riyadh airport were canceled in the past 24 hours, according to flight tracking site FlightAware. Before the latest attack, Air India, FlyDubai, Lufthansa Group and Pakistan International Airlines were among the airlines suspending flights to and from Riyadh and other Saudi airports for varying periods.

The European Union Aviation Safety Agency has expanded its guidelines on Saudi airspace, noting the Houthis’ ability to strike targets deeper inside the kingdom, including Riyadh, and a “greater focus on air infrastructure.”

Missile and drone attacks and interception efforts “create an increased risk of misidentification of civilian aircraft,” he said.

Saudi Arabia’s national airline said one of its planes was damaged while on the ground with no passengers on board.