By Gianluca Lo Nostro, Menna AlaaElDin and Joanna Plucinska
Oct 12 (Reuters) - Authorities have extended the closure of Riyadh's international airport until Saturday and airlines scrapped flights after continuing attacks by Yemen's Iran-aligned Houthis emptied the skies over Saudi Arabia's capital.
Operations at King Khalid International Airport, Saudi Arabia's second-busiest airport 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 in a statement.
A Notice to Airmen (NOTAM) issued later in the day showed that the airport will stay closed until 2100 GMT on October 17.
The airport has been shut since an attack on Saturday that killed 13 people and wounded more than 300, the deadliest in the kingdom in more than a decade. On Sunday, another attack killed one person and injured nearly a dozen others.
The attacks marked one of the most significant disruptions to Saudi aviation in years, adding to pressures on an industry already grappling with conflict across the Middle East and with higher jet fuel prices that are eating into profits.
They have also raised worries over 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, a membership-based 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 planes avoiding the city on Monday, though jets were crossing Saudi airspace and landing at top hub Jeddah on the country's west coast.
Cancellations across all Saudi airports reached 46.4%, aviation analytics firm Cirium said.
CRISIS OVERSHADOWS SAUDI BUSINESS OUTLOOK
The disruption has forced airlines across Europe and Asia to suspend services, while the Federal Aviation Administration advised US carriers on Sunday to exercise caution when flying to or over Saudi Arabia. EU aviation body EASA widened a Saudi airspace warning on Friday, 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 take a route from Europe to Asia over central Asia.
That adds "extensive distance" for some routes and "closes off options for getting into Dubai, Abu Dhabi for most western carriers," Zee said.
Lufthansa Group has cancelled all flights to Riyadh until October 16, while Air France-KLM has extended a suspension to and from Riyadh until the end of the month. Abu Dhabi's Etihad Airways also extended cancellations.
Delta Air Lines said it was delaying planned services from Atlanta to Riyadh, initially due to start on October 23, until March 2027.
The escalation with the Houthis has raised concerns over the broader economic impact. Saudi Arabia's real GDP is projected to contract by 3.6% this year, reflecting a combination of factors including lower oil activity.
The attacks have put events scheduled in Riyadh this month under pressure, including the kingdom's flagship investment conference and the WPC Energy Congress, where several top oil executives were dropped from the programme.
(Reporting by Joanna Plucinska in London, Gianluca Lo Nostro in Gdansk, Federico Maccioni in Dubai and Menna Alaa El Din in Cairo; Editing by Matt Scuffham, Aidan Lewis)
