Yemen's Iran-aligned Houthis escalated their campaign of strikes against Saudi Arabia on Thursday, trying to shut down the kingdom's airspace and oil facilities with missile fire that has killed three people this week.
The group said it had struck Riyadh airport, where witnesses saw smoke billowing from a plane, and it warned workers to stay away from energy plants. Saudi officials said debris from an intercepted missile had hit a kindergarten and medical complex.
The Houthis say they are targeting the kingdom over its support for government forces in Yemen's reignited civil war. Saudi Arabia says it is backing an offensive by Yemen's UN-recognised government to take back territory from the Houthis.
The conflict, now an overspill of the US-Iran war, has added new chaos to a region already aflame, and threatens to draw other states into gruelling mountain fighting - with Syria now considering deploying troops to assist Saudi Arabia.
The kingdom has pushed for support from allied nations, including Turkey and Pakistan, even if only in a logistical or defensive capacity, as it tries to reverse Houthi gains in southwest Yemen, by the southern entrance to the Red Sea.
Those requests have taken on more urgency since Saudi authorities said on Wednesday that three people had been killed this week in strikes on Riyadh airport and Abha airport in the southwest.
CIVIL WAR REIGNITED BY CONFLICT IN IRAN
The Houthis have made Saudi airports a major focus of their strikes, and the Saudi-led coalition fighting in Yemen said it had destroyed two ballistic missiles launched by the group towards Riyadh and another towards Khamis Mushayt, home to a major airbase.
The smoke at Riyadh airport on Thursday was rising from a stationary aircraft that was believed to be empty, three people briefed on the matter said. The fire had since been put out, they said.
There was no immediate confirmation from Saudi authorities on the Houthi claims of ballistic missile attacks on Riyadh airport and the cause of the smoke billowing from the plane was not immediately clear.
However, the flight tracker FlightRadar24 indicated numerous delayed arrivals and departures at Riyadh's King Khalid International Airport on Thursday. The airport advised travellers to contact airlines to check the status of flights before trying to travel.
Saudi authorities said debris from an intercepted Houthi missile had landed in Riyadh, causing damage to a kindergarten and a medical clinic complex, state media reported.
Riyadh is due to host a major meeting of energy policy makers, the WPC Energy Congress, this week.
Several mulitinational firms based in Riyadh's King Abdullah Financial District (KAFD) told staff to work from home after loud booms were heard on Thursday morning, five people familiar with the matter said, including some affected staff.
The Saudi government did not respond to a request for comment, and KAFD was not immediately available for comment.
Some diplomats said they had received warnings, and some schools in Riyadh told parents there were orders to shelter in place, though authorities did not issue a public alert. Reuters could not identify the source of the booms.
The Houthis also warned workers to stay away from oil facilities in Saudi Arabia, saying they would be targeted.
Yemen's long-running civil war, which paused with a ceasefire in 2022, has erupted again in recent weeks with the Houthis seizing stretches of the Red Sea coast last month, including along the vital Bab el-Mandeb Strait.
The Houthis have said they were responding to attacks from the Saudi-backed government, which the government denies.
Their threats to shipping and attacks on Saudi cities and infrastructure, have drawn the kingdom back in. This week, Saudi-backed forces launched a counter attack, taking back areas around the strait.
However, in a war with several frontlines, the Houthis have made gains of their own, surrounding Yemen's third-largest city, Taiz, by taking territory along its main mountain road to Aden.
The fighting, which pits the Houthis against a coalition of Saudi-backed forces under the internationally recognised government, has led to a humanitarian crisis in the poorest Arab state, displacing 200,000 people since the conflict resumed.
OFFICIALS SAY SYRIAN AID MIGHT BE PURELY DEFENSIVE
One US and one Syrian defence official said Syria was carefully considering options for military support, including defensive aid to protect Saudi Arabia from attacks, or an offensive deployment to help take the fight to the Houthis.
In response to a request for comment to the Syrian foreign ministry, a diplomat said Syria stood firmly with Saudi Arabia but that its focus was on domestic priorities such as recovery from its own civil war.
NATO-member Turkey said on Wednesday it was sending mainly defensive and technical support to the kingdom to help in the fight against the Houthis. A Turkish official said this was expected to take the form of military equipment, intelligence sharing and weapons systems.