Several people have been injured in another attack on an international airport in the Saudi capital Riyadh, reports say, days after Yemen’s Houthis claimed to have carried out strikes on the hub.

King Khalid International Airport in Riyadh was evacuated after a loud blast was heard on Saturday, two international news agencies have reported.

More than a dozen ambulances were seen rushing to the airport, according to Reuters, citing an eyewitness. Saudi authorities have not commented, while the airport told passengers to check with their airline before travelling there.

The US embassy said it was “aware of attacks on King Khalid International Airport” and urged American citizens to avoid the airport and surrounding areas.

The attack comes a day after authorities said three Saudis including a pilot were killed in two attacks on the airport by the Iran-backed Houthis the day prior. Another three people were killed in Houthi attacks on two Saudi airports on 6 and 7 October.

A source at a local hospital told news agency AFP that dozens of people had been wounded in Saturday’s attack.

“I saw 401 hit, I saw injured in front of my eyes. Everyone was running,” an eyewitness who said they had been at gate 401 in the domestic terminal told AFP.

While there has been no official confirmation of an attack, western embassies in Saudi Arabia have warned their citizens away from the airport.

Several Gulf airlines said they had cancelled their flights to and from the airport. with Kuwait Airways citing the “security situation” there.

All flights to Riyadh have either been diverted or cancelled, aviation tracker Flightradar shows.

Doctors had been asked to report to hospitals to address the situation, a medical source told AFP.

“We were told we are dealing with a ‘serious emergency situation’,” the medical source told the agency.

The suspected attack comes during a marked escalation in renewed fighting between Yemen’s Saudi-backed government forces and the Houthis, who control most of the country’s north-west.

The Houthis say they are targeting Saudi Arabia over its support for government forces in Yemen’s civil war.

The conflict worsened after the Houthis seized strategically important stretches of the Red Sea coast in a rapid offensive.

That included the port of Mokha on the Bab al-Mandab Strait, which is the narrowest point of the Red Sea and a chokepoint for global shipping. Yemeni pro-government forces have since said they had “secured” the strait at the southern end of the Red Sea.

A Saudi-led coalition was formed in 2015 after Arab countries joined forces to stop the Houthis taking over Yemen from the country’s internationally recognised government.

A temporary ceasefire was brokered in 2022 after years of air strikes and ground fighting led to the deaths of hundreds of thousands of people, triggering one of the world’s worst humanitarian crises.

But the informal truce began to unravel in July.

The Houthis announced a “maritime embargo” against Saudi Arabia and began missile and drone attacks on Saudi airports, oil facilities and tankers in the Red Sea. They said they were retaliating against what they described as a years-long Saudi blockade and for an air strike on Sanaa airport.