CAIRO (AP) — A wave of attacks by the Iranian-backed Houthis on Saudi Arabia early Tuesday wounded 73 people, Saudi authorities said.

Maj. Gen. Turki al-Malki, a spokesman of the Saudi-led coalition fighting in Yemen, said the rebels have targeted “civilian and economic facilities” in the Saudi cities of Abha’s Jazan, Najran and Khamis Mushait.

He said the Saudi-led coalition “will take all necessary operational measures to deter the terrorist Houthi militia with utmost resolve.”

The Houthi attacks came after the rebels accused Saudi Arabia of attacking a prison in Yemen’s northern province of Jawf.

The attacks came amid a weekslong escalation of fighting between the Houthis and Saudi-backed government forces in Yemen which shattered a four-year truce in the civil war there.