Circuit Wire — a daily news update from the Circuit.

The US Embassy in Beirut told Americans on October 18 to exercise heightened vigilance across the Middle East, warning that flights may be cancelled and airspace closed, in a security alert describing a complex security environment.

The alert says Iran-supported Houthi forces have attacked Saudi Arabia, including civilian airports and critical infrastructure. It says those strikes caused civilian casualties and severe travel disruption, and that hostilities could escalate quickly.

The embassy also warned that Iran and aligned groups may target US interests, businesses and institutions worldwide, not only in the region. The alert says the embassy remains open for routine American citizen and visa services. It notes that Lebanon remains under a Level 4 "Do Not Travel" advisory from the State Department.

The alert lists steps for Americans in the region. It advises checking flight status with the airline or Beirut Rafic Hariri International Airport, enrolling in the State Department's STEP program, and following the embassy's alerts archive and local media.

After an aerial attack, it advises staying away from windows, glass doors and debris. It also advises avoiding demonstrations, large gatherings and areas with heavy police presence, and keeping a low profile near US-associated locations.

The embassy listed its own number as +961-4-543-600. The State Department's Consular Affairs line is +1-202-501-4444 from abroad and 1-888-407-4747 from the US and Canada. Lebanon's Internal Security Forces can be reached at 112.

The warning follows a run of Houthi attacks on Saudi aviation that we have tracked. A Houthi strike on Riyadh airport killed 12 and wounded more than 300. The US Embassy then reported new attacks on Riyadh and Dammam airports, and later said Americans were detained for filming the attacks.

Want a weekly roundup of the major stories shaping the security industry? The On The Circuit newsletter is read by more than 12,000 protection professionals.

Spotted something we should cover? Send tips and feedback via circuit-magazine.com.