A Saudia Airlines aircraft was left heavily damaged by fire at a terminal of King Khalid international airport on Thursday, the riyadh airport attack claimed by Yemen's Houthis having left its mark on a parked commercial jet.

Shrapnel left Saudia plane burned at the terminal

Three people briefed on the matter told Reuters that shrapnel, from an interception or another projectile, set the parked Saudia Airlines plane alight and left it heavily damaged.

According to those same sources, no passengers were believed to have been aboard the aircraft when it caught fire, though injuries could not be ruled out.

The Houthis say they hit King Khalid international airport with a ballistic missile and badly damaged a plane. The group offered no evidence for the claim, and Saudi Arabia did not immediately comment on it.

Explosions, smoke and evacuation at the airport

Witnesses in Riyadh reported hearing explosions, among them a large blast at King Khalid international airport. One witness told the Associated Press that fire and ambulance crews were sent to the scene.

A video verified by Reuters showed two things rising from the airport grounds:

• •a thick black column of smoke
• •visible flames

An anonymous witness said outgoing flights were halted and that passengers were instructed to evacuate the airport.

Carriers halt flights as cancellations mount

Two international carriers confirmed they were pulling services from the Saudi capital:

• •Lufthansa said it was suspending flights to Riyadh
• •Air India confirmed it was suspending flights to Riyadh

Cirium data showed that almost half of departures from the airport had been cancelled by 1500 GMT on Thursday. A further 31 cancellations were expected for Friday across all Saudi airports.

The disruption comes as Riyadh is due to host the WPC Energy Congress, a major meeting of energy policymakers, this week.

Escalation on the ground in Yemen

Saudi authorities said on Wednesday that three people had been killed this week in strikes on Riyadh airport and Abha airport in the southwest. Saudi officials also said debris from an intercepted missile had hit a kindergarten and medical complex in Riyadh.

On Thursday the Houthis attempted to shut down the kingdom's airspace and warned workers to stay away from energy plants, which they said would be targeted.

The Houthis describe their campaign as a response to Saudi backing for government forces in Yemen's reignited civil war. Saudi Arabia, for its part, says it is supporting an offensive by Yemen's UN-recognised government to retake ground from the group.

The Houthis have appeared to gain ground in the country's south-west over the past month, approaching the city of Taiz on Wednesday. Independent observers said earlier this week that the group risked capturing Taiz, with some signs that forces linked to the Saudi Arabian-backed government were pulling back to secure the major port city of Aden.

The Houthis offered no evidence for their airport claim, and Saudi Arabia did not immediately comment, while 31 further cancellations remained expected for Friday across all Saudi airports.