Young Yemenis shout slogans Saturday during a rally in Sanaa to protest ongoing military by a Saudi-led coalition. Houthi rebels fired a Scud missile into Saudi Arabia early Saturday. (Yahya Arhab/European Pressphoto Agency)

In a potentially major escalation of the months-long war, Yemeni Houthi rebels fired a Scud missile into Saudi Arabia early Saturday, in apparent retaliation for more than two months of airstrikes by Saudi-led forces.

According to the official Saudi Press Agency, two missiles launched from a Patriot missile battery shot down the Scud before dawn near the southwestern city of Khamis Mushait. The agency did not report any casualties in the attack.

Khamis Mushait is home to the King Khalid Air Base, the largest such facility in that part of the country. Saudis on social media reported hearing air raid sirens go off around the city during the attack. The coalition responded to Saturday’s attack by targeting and damaging the Scud launcher, which was found south of the Houthi stronghold city of Saada, according to SPA.

It was the first use of a Cold War-era Scud by the rebels since Saudi-led airstrikes targeting the Houthis began in late March.

Yemen’s state news agency SABA, now controlled by the Houthis, said the rebels fired the Scud. The Houthis are allied with military and security forces loyal to former Yemeni President Ali Abdullah Saleh.

Saudi Arabia has been leading the coalition carrying out airstrikes in support of Yemen’s exiled president, Abed Rabbo Mansour Hadi. Those strikes have targeted arms caches and Scud missile sites across the country.

The Yemeni military was widely believed to possess about 300 Scud missiles, most of which fell into the hands of the rebels.

In April, the spokesman for the coalition, Saudi Brig. Gen. Ahmed Asiri, implied that the Scud arsenal in Yemen had been seriously degraded as a result of the airstrikes.

On Saturday, Asiri told the Saudi-owned al-Hadath news channel that coalition forces have destroyed “most of” Yemen’s Scuds.

The Saudis and Western powers accuse the Houthis of receiving military support from Shiite power Iran as part of a larger proxy war between the Sunni kingdom and the Islamic Republic across the Mideast. Tehran and the rebels deny the allegations, though Iran has acknowledged sending humanitarian aid to the Houthis.

The Saudi-led air campaign and ground fighting have killed more than 1,000 civilians and displaced more than 1 million people since mid-March, according to the United Nations.

The offensive, now in its third month, has so far failed to force the Houthis to withdraw from any territory they hold or to blunt their advance in southern Yemen.

— Associated Press