CAIRO (AP) — Three Saudi citizens were killed and several other people were wounded in two attacks Thursday targeting King Khalid International Airport in Riyadh and a Saudia Airlines aircraft, Saudi Arabia’s General Authority of Civil Aviation said Friday.

It marked the deadliest attack in the country since Saudi Arabia and allied forces in neighboring Yemen launched a major military offensive last weekend against the Iran-backed Houthi rebels in that country.

The first attack on Thursday targeted airport facilities, while the second struck the aircraft, the statement said. It did not identify those responsible, though the Houthis claimed to have targeted the airport with a ballistic missile.

The airport has come under multiple attacks, with a Sudanese national killed there earlier this week.

The new statement noted “injuries to a number of citizens and residents of different nationalities. Their injuries ranged from minor to serious.”

It also indicated that operational activities had returned to normal.