RIYADH — Saudi Arabia conducted airstrikes against Houthi military targets in Yemen on Wednesday following attacks the kingdom said threatened Mecca and Medina, according to the Saudi Defence Ministry. The operation aimed to protect Islam's two holiest cities.

The strikes came days after Saudi Arabia condemned what it described as Houthi assaults on the holy sites and vowed to defend the kingdom. The Iran-aligned Houthi movement has intensified its regional operations as the broader conflict involving Iran has escalated.

Saudi state television reported that air defences intercepted projectiles over the southwestern provinces before the retaliatory operation began. The Houthis' Al-Masirah broadcaster said coalition aircraft hit sites in and around Sanaa, the Yemeni capital under Houthi control.

The exchange represents the most serious flare-up between Saudi Arabia and the Houthis since a fragile United Nations-brokered truce largely held in recent years. Gulf diplomats warned that renewed Saudi involvement could unravel efforts to end Yemen's long civil war.

A Saudi-led coalition spokesperson said forces would continue operations "as long as the threat to the two holy mosques persists" and urged civilians near Houthi military installations to evacuate.