.@StateDept updated 13 travel advisories throughout the Middle East to "reflect an increase in potential armed attacks by the Iranian-supported Houthis and Iranian efforts to target U.S. government officials in the region."

A State Department Official adds that "The possibility of regional effects [of Houthi attacks], including the potential for flight disruptions, makes a region-wide advisory update important and prudent."

The Official also notes ongoing warnings about Iranian drones and missiles, and says "We have consistently messaged to Americans on the threat from Iran and will continue to do so."
https://travel.state.gov/en/international-travel/travel-advisories.html