The GACA announced that Riyadh had suspended operations at its main airport on Oct. 10 and was assessing the damage; FlightAware showed 400 cancellations into and out of KKIA as of 11 p.m. local time.

The U.S. Embassy in Riyadh also issued a security alert, warning Americans to avoid KKIA and its surrounding areas that same day. 

“U.S. citizens should be aware of potential flight cancellations, airspace closures, and travel disruptions. We recommend checking your flight departure status directly with the airline and with the airport,” its website said.

The latest airport attacks followed months of escalating threats to air travel and shipping. 

In July, the Houthis accused the Saudis of bombing Sanaa International Airport. Yemen’s Saudi-backed government claimed responsibility, saying it had sought to prevent an Iranian plane from landing there. 

In response, the Houthis said that they would impose a naval blockade on Saudi Arabia.