More than a dozen ambulances rushed to Riyadh International Airport on Saturday after a loud blast was heard at the facility, while travellers were evacuated from parts of the airport, according to an eyewitness and people briefed on the incident. The incident comes amid escalating missile attacks by Yemen’s Iran-aligned Houthi group on Saudi Arabia. The airport was attacked twice earlier this week, killing four people, injuring others and severely damaging an aircraft. Saudi Arabia’s government media office and civil aviation authority did not immediately respond to requests for comment on Saturday’s blast. Flight-tracking website Flightradar24 showed that flights heading to Riyadh had been diverted or cancelled. At one point, only a helicopter was seen hovering over the airport. Airport authorities urged passengers to contact their airlines and check flight status before travelling to the facility. Multiple flights cancelled Etihad Airways and Qatar Airways cancelled multiple flights between their respective hubs and Riyadh, with some cancellations extending into Monday. Houthi attacks on Thursday and earlier this week had already prompted several airlines to suspend or cancel services to the Saudi capital, which is scheduled to host major energy and investment conferences. Organisers said on Saturday that the events would proceed as planned and sought to reassure attendees about security arrangements. The Houthis have warned airlines to 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. Post navigation 9 killed, including children, in US mass shooting:Suspect also shoots himself; over 320 killed in mass shootings this year