Region-wide warning

The United States has warned Americans across the Middle East to exercise heightened vigilance, citing the increased threat of armed attacks by Iranian-supported Houthis and Iranian efforts to target US government officials in the region. Identical security alerts were issued on Friday evening by US missions in Iran, Iraq, Saudi Arabia, Lebanon and Israel. They warn of potential flight cancellations, airspace closures and travel disruptions, and say the Houthis have attacked civilian airports and other critical infrastructure in Saudi Arabia, causing civilian casualties and severe travel disruption.

Leave Iran now

The alert for Iran is the bluntest: "Do not travel to Iran for any reason. US citizens should leave Iran now." It warns that border-crossing procedures at Iran's land borders may change with little notice, and that Iran and groups supportive of Iran may target other US interests overseas, including US businesses and other institutions.

What Americans are told to do

Americans in the region are told to enrol in the State Department's Smart Traveler Enrollment Program, monitor local media, avoid demonstrations and large gatherings and areas with a heavy police presence, keep a low profile and check flight departure status directly with their airline. The Saudi Arabia alert notes that on 23 October the State Department ordered non-emergency US government employees and their family members to leave the kingdom because of safety risks.