At least 12 people have been killed and 309 others injured in an attack on King Khalid International Airport in Riyadh, Saudi Arabia, prompting a Saudi-led coalition to threaten a decisive response against Yemen’s Houthi rebels.

The coalition blamed the Iran-backed group for the attack, describing it as a “full-fledged war crime”, while a diplomatic source attributed the strike to a missile.

The incident occurred amid escalating Houthi attacks on Saudi Arabia following the collapse of a truce in July in the long-running conflict between the rebels and Yemen’s internationally recognised government, which is backed by Riyadh.

The renewed violence has heightened fears of a wider regional conflict, with US President Donald Trump indicating that Washington could join military action against the Houthis.

A passenger who spoke to AFP said they witnessed the strike at the airport’s domestic terminal.

“I was on gate 403. I saw 401 hit, I saw injured in front of my eyes. Everyone was running,” the witness said.

Saudi Arabia’s civil aviation authority said the fatalities included four Saudi citizens, two Bangladeshis and one citizen each from the United States, Egypt, Jordan, Syria and Sudan, as well as one Palestinian. Some of the 309 injured were reportedly in serious condition.

Airport operations were suspended following the attack as authorities assessed the damage.

A medical source said health officials had activated an emergency call-up of doctors to respond to the incident. Two doctors also told AFP that several pilgrims travelling to Mecca were among the injured.

Schools across Riyadh switched to remote learning for the second time in a month. Parents received emails citing an education ministry directive requiring schools in the capital to conduct lessons online throughout the week.

Coalition Threatens Retaliation

The Saudi-led coalition’s spokesperson, Major General Turki al-Malki, condemned the attack in a statement posted on X.

He described the incident as a “cowardly terrorist attack” by the Houthi militia, alleging that it had caused deaths and injuries among civilian passengers and airport personnel.

The coalition had earlier announced that it intercepted missiles targeting Saudi Arabia and destroyed launch platforms.

The Houthis claimed responsibility for a series of attacks targeting the airport on Thursday, which reportedly killed three people and damaged an aircraft. However, the group had not immediately claimed responsibility for the latest strikes reported on Saturday.

The attack was described as the deadliest on Saudi soil since May 2015, when a suicide bombing claimed by the Islamic State militant group killed 21 worshippers at a Shia mosque in Qatif.

Trump Signals Possible US Involvement

Yemen’s civil war intensified again in July following the collapse of a four-year United Nations-brokered truce, amid wider conflict in the Middle East that has disrupted regional security and energy markets.

Saudi Arabia has led a military coalition supporting Yemen’s internationally recognised government since 2015 and is now facing renewed security challenges as the conflict escalates.

Asked on Saturday whether he had changed his position on joining Saudi strikes against the Houthis, Trump replied, “We may.”

He said he planned to speak with Saudi Crown Prince Mohammed bin Salman, describing the attack as “not acceptable”.

US media reports have indicated that previous Saudi requests for American military assistance against the Houthis had been rejected.

The US, Canadian, German and Spanish embassies in Saudi Arabia warned their citizens to avoid the airport following the attack.

A senior Western diplomat told AFP that several embassies were prohibiting their staff from using the airport for the following week.

Pakistan’s Prime Minister, Shehbaz Sharif, condemned what he described as a “heinous attack” and reaffirmed Islamabad’s commitment to Saudi Arabia’s security under their defence pact.

Fighting Escalates Near Bab al-Mandab Strait

The attack came shortly before Saudi Arabia’s annual convention and entertainment season, which begins this month and includes a major investment conference attended by foreign leaders and business executives.

Meanwhile, Saudi-backed Yemeni government forces were advancing against the Houthis in areas around the Bab al-Mandab Strait, which the rebels reportedly captured last month, according to military sources cited by AFP.

The Yemeni government announced a counter-offensive last week aimed at recapturing territories held by the Houthis.

The rebels confirmed that government forces had launched attacks in the Bab al-Mandab area but claimed to have repelled the offensive.

The strategic strait is a major passage for oil and cargo shipments through the Red Sea. However, claims by the warring parties have been difficult to verify independently because of rapidly changing battlefield conditions and limited access for journalists.