A terror attack on a passenger terminal at the international airport in the Saudi Arabian capital of Riyadh killed 12 and injured more than 300, the Saudi-led coalition forces in Yemen said Sunday. The coalition government blamed the attack on Iran-backed Houthis in Yemen.

The attack late Saturday on King Khalid International Airport “constitutes a full-fledged war crime according to the Customary International Humanitarian Law,” spokesman for the Saudi-led Arab coalition forces Col. Turki Al-Maliki said in a statement on X.

U.S. Secretary of State Marco Rubio condemned the attack.

The coalition forces said in its statement that in addition to the American, the deceased included four Saudi citizens, two Bangladeshi nationals, a Palestinian, an Egyptian, a Jordanian, a Syrian, and a Sudanese.

The group said the injured were being treated at several hospitals. Civil aviation authorities said early Sunday that some were in critical condition.

The coalition forces responded with operations targeting the Houthis’ ballistic missile capabilities and weapons storage.

“We are working to dismantle and destroy the ballistic missile network of the terrorist Houthi militia,” Al-Maliki said in an Oct. 9 statement on X. He said that 136 military targets had been destroyed.

The Houthis have not claimed responsibility for the latest attack.

“Please take extreme caution when using all major airports in Saudi Arabia,” it added.

Shortly after the attack, President Donald Trump was asked if the United States would join Saudi strikes against the Houthis. “We may. We’re going to look at it,” he told reporters. “We just found out about the recent attack. So we’ll make a decision. We move very quickly.”

Later, Trump said he planned to speak to Saudi Crown Prince Mohammed bin Salman about the attack.

“What happened in Saudi Arabia is not acceptable,” he told reporters.

The deaths make it the deadliest attack on any Gulf Arab country since the start of the Iran war in February. The conflict has recently escalated to a new battlefront at the Saudi–Yemen border and the Red Sea, with the Houthis fighting the coalition government forces.

U.N. Secretary-General António Guterres said in a statement Sunday: “Attacks on civilians & civilian infrastructure are a violation of international law. These attacks must cease immediately.”

The Council of Arab Interior Ministers, representing the 22 member nations of the League of Arab States, condemned the attack.

Muslim World League Secretary-General Mohammed Al-Issa said the terrorist act violates “all religious values, international laws, and humanitarian norms,” and reflects “the criminal approach of this terrorist militia in deliberately targeting civilians and civilian infrastructure.”