Iran-backed Houthi rebels in Yemen claimed Wednesday that they had launched attacks against military installations and airports in neighboring Saudi Arabia, adding another dangerous dimension to the expanding regional conflict involving Iran. The attacks also threatened a key alternative shipping route near the Bab el-Mandeb Strait, amid continued disruptions around the Strait of Hormuz.

Houthi military spokesperson Brig. Gen. Yahya Saree said on social media that the group had fired ballistic missiles and launched drones toward King Khalid International Airport in Riyadh. He offered no evidence to substantiate the claim.

Flight-tracking service Flightradar24 reported brief disruptions to flights arriving at and departing from the Riyadh airport.

Saree also said Houthi forces targeted Abha airport, which has repeatedly come under attack from Houthi missiles and drones. The rebels further claimed strikes against an air base in Khamis Mushait and military facilities in Najran and Asir. The sites are located in southwestern Saudi Arabia near Yemen’s border.

Maj. Gen. Turki al-Malki, spokesperson for the Saudi-led coalition fighting the Houthis, said coalition forces intercepted and destroyed a ballistic missile north of Riyadh.

Saudi Arabia and allied Yemeni forces have launched an extensive ground and air campaign against the Houthis in recent days, seeking to recover territory the rebels captured roughly a month ago along Yemen’s western Red Sea coast and near the Bab el-Mandeb Strait. Control of those areas has strengthened the Houthis’ ability to monitor maritime traffic as they seek to disrupt Saudi shipping.

Coalition officials said Monday that their forces had retaken several strategically important positions near the strait.

Since then, much of the fighting has focused on Dhubab, a strategically located town roughly 30 miles south of the port city of Mokha, according to both Houthi representatives and Yemen’s internationally recognized government.

Fighting has also been reported in Waziayah district in southwestern Taiz province. The area connects Yemen’s mountainous interior with the Red Sea and provides views toward routes leading to the Bab el-Mandeb Strait.

The Houthis separately claimed early Wednesday that they had launched a missile attack on Aden, the southern port city that serves as the headquarters of Yemen’s internationally recognized government. An Associated Press journalist reported hearing explosions at approximately 2 a.m. local time, or 7 p.m. Tuesday Eastern Time.

Saree said ballistic missiles struck a military camp near Aden’s airport.

Security officials in Aden said two missiles were fired toward the airport but caused no casualties. The facility is located close to government offices.

“The targeting of this vital civilian facility represents a direct threat to the safety of civilians, passengers, employees and flight crews,” the Aden police said in a statement.

Yemen’s Human Rights Ministry warned that the airport strike could lead to “a humanitarian disaster,” saying one missile landed near the runway shortly before a flight from Cairo was scheduled to arrive.

Flight 603, operated by Yemen’s national airline, landed safely in Aden at 3:30 a.m., according to FlightAware.

The ministry said the missile struck while other travelers were waiting to board a flight bound for the Saudi coastal city of Jeddah.

“The Houthis believe that they can maximize Saudi economic costs and compel Saudi Arabia to surrender to Houthi demands by striking civilian infrastructure, such as oil facilities and airports,” the Institute for the Study of War, a Washington-based think tank, wrote in an analysis.