More than a dozen ambulances were seen rushing to Riyadh's international airport, and travelers were evacuated from parts of the facility after a loud blast was heard there on Saturday, an eyewitness and people briefed on the matter said.
Saturday's incident comes amid an escalation of missile strikes by Yemen's Iran-aligned Houthi on the kingdom. The airport has already been attacked twice this week, leaving four people dead and others wounded, and badly damaging an aircraft.
The Saudi government's media office and the Saudi civil aviation authority did not immediately respond to requests for comment on the incident.
Flight tracking site flightradar24 showed all flights to Riyadh had either been diverted or canceled, with only a helicopter hovering over the airport at one point.
The airport urged passengers to contact their airlines directly and check their flight status before heading there.
Etihad Airways, Qatar Airways, Kuwait Airways cancel Riyadh flights amid Houthi attacks
Etihad Airways and Qatar Airways canceled multiple flights between their respective hubs and Riyadh, with some cancellations extending into Monday.
Kuwait Airways said on Saturday it had canceled flights to and from the Saudi capital Riyadh due to what it described as the closure of Riyadh airport because of the "security situation."
Houthi attacks on Thursday and earlier in the week had already prompted a number of carriers to suspend or cancel services to the Saudi capital, shortly before Riyadh is due to host major energy and investment conferences.
Organizers of those conferences said on Saturday they would go ahead as planned, and they sought to reassure attendees of their security.
The Houthis have said airliners should avoid Saudi airspace, declaring it a zone of military operations after the Saudi-backed Yemeni government launched an offensive against the group earlier this month.
US Embassy warns Americans to avoid Riyadh airport following attacks
The US Embassy in Riyadh issued a security alert Saturday, advising American citizens to avoid King Khalid International Airport and surrounding areas following reported attacks on the airport, according to a post on X/Twitter.
The embassy said US government employees based in Riyadh must obtain special authorization to use the airport.
The alert also warned travelers to expect flight cancellations, airspace closures, and other travel disruptions.
US government employees in Saudi Arabia are prohibited from traveling within 20 miles of the Yemeni border due to security risks. They also require special authorization to visit the provinces of Jizan, Asir, and Najran, as well as the cities of Qatif, Yanbu, and Taif.