RIYADH — At least 12 people were killed and 309 others wounded yesterday in a strike on Riyadh’s international airport, Saudi Arabia’s civil aviation officials said — an attack that a diplomatic source blamed on Yemen’s Houthis.

Four Saudi citizens were among the dead, as well as two Bangladeshis, one US citizen, one Egyptian, one Jordanian, one Syrian, one Palestinian and one Sudanese, the statement added. Some of the wounded were in serious condition.

The Iran-backed Houthis have unleashed a wave of strikes against the kingdom on an unprecedented scale, targeting Saudi airports, oil facilities and tankers since a truce in their long-running war with Yemen’s Riyadh-backed government unravelled in July.

Admissions by Saudi authorities of strikes hitting civilian targets are relatively rare, and aviation officials did not mention the Houthis by name.

The diplomatic source attributed the attack to a Houthi missile.

Operations were suspended at the sprawling King Khalid International Airport following the attack, the Saudi civil aviation authority said earlier.

Damages were still being assessed.

The attack prompted health officials to activate a rare mass call-up of doctors to deal with the “serious emergency situation”, a medical source said.

Foreign embassies warned their citizens to avoid the airport.