RIYADH, Saudi Arabia: Saudi Arabia has extended the closure of Riyadh's King Khalid International Airport until October 17 after deadly Houthi attacks, forcing airlines to cancel services and disrupting one of the kingdom's main aviation hubs.

Operations at the airport, Saudi Arabia's second busiest after Jeddah, were suspended to "allow for the completion of procedures to ensure the safety and operational readiness of the airport's facilities", the Saudi civil aviation authority said.

A Notice to Airmen issued later in the day showed the airport would remain closed until 2100 GMT on October 17.

The airport has been shut since an attack on October 10 killed 13 people and wounded more than 300, the deadliest in the kingdom in more than a decade. Another attack on Sunday killed one person and injured nearly a dozen others.

The attacks have caused one of the most significant disruptions to Saudi aviation in years, adding pressure to an industry already dealing with conflict across the Middle East and higher jet fuel prices that are cutting into profits. They have also raised concerns about civil aviation becoming a target in armed conflict.

"This level of sustained intense attack on civil aviation is unprecedented," said Mark Zee, founder of OPSGROUP, an organization that provides aviation safety advice.

"I think this requires us to rethink how we view the current risk picture, and tread very carefully," he said.

Air traffic tracker Flightradar24 showed aircraft avoiding Riyadh on October 12, although jets continued to cross Saudi airspace and land at Jeddah on the country's west coast.

Cancellations across all Saudi airports reached 46.4 percent, according to aviation analytics firm Cirium.

The disruption has prompted airlines across Europe and Asia to suspend services. The U.S. Federal Aviation Administration advised American carriers on October 11 to exercise caution when flying to or over Saudi Arabia, while EU aviation body EASA widened an airspace warning for the country on October 10, citing missile and drone attacks.

"The impact goes beyond Saudi Arabia to the wider region and to its global connections," said aviation analyst John Strickland.

OPSGROUP advised airlines to avoid the southern aviation corridor over the Middle East altogether and instead fly over Central Asia between Europe and Asia.

That adds "extensive distance" to some routes and "closes off options for getting into Dubai, Abu Dhabi for most western carriers," Zee said.

Lufthansa Group has canceled all flights to Riyadh until October 16, while Air France-KLM has extended its suspension of services to and from the Saudi capital until the end of the month. Etihad Airways in Abu Dhabi has also extended cancellations.

Delta Air Lines said it was postponing its planned Atlanta-Riyadh service from its original October 23 launch until March 2027.

The escalation with the Houthis has also raised concerns about the wider impact on Saudi Arabia's economy. The country's real GDP is projected to contract by 3.6 percent this year, reflecting several factors, including lower oil activity.

The attacks have put pressure on events scheduled in Riyadh this month, including the kingdom's flagship investment conference and the WPC Energy Congress, where several top oil executives were dropped from the program.