CAIRO (AP) — The airport in the Saudi capital has been attacked again, two regional officials said Saturday, two days after three Saudi citizens including a pilot were killed there.

One official said the Riyadh airport had been evacuated, and the other said air traffic had stopped. They spoke on condition of anonymity because they weren’t authorized to speak to the media.

King Khalid International Airport has been targeted in an extraordinary series of attacks in the week since a Saudi-led coalition launched a major military offensive against Iran-backed Houthi rebels in neighboring Yemen.

The Houthis claimed responsibility for the earlier attacks, including another on Wednesday that killed a Sudanese national and wounded eight other people.

There was no immediate Houthi statement Saturday.

A Riyadh resident, Ahmed Sayed, told The Associated Press he heard at least two loud explosions that rocked the capital.

The airport issued a terse alert telling passengers to check their flight status with airlines before heading to the airport.

Fighting in Yemen between the Houthis and the Saudi-backed Yemeni government forces has escalated, with the Saudi-led coalition providing air support for government forces in an attempt to reverse recent Houthi gains along the Red Sea.