Washington's security warning about Iran and Yemen "American citizens who are currently in the Middle East should increase their vigilance due to the increased threat of armed attacks by the Houthis, as well as Iran's efforts to harm US government officials in the region," the embassy statement said. The American Embassy in the United Arab Emirates added: "Be aware and vigilant about the possibility of flight cancellations, airspace closures and travel disruptions."

Washington's security warning about Iran and Yemen "American citizens who are currently in the Middle East should increase their vigilance due to the increased threat of armed attacks by the Houthis, as well as Iran's efforts to harm US government officials in the region," the embassy statement said. The American Embassy in the United Arab Emirates added: "Be aware and vigilant about the possibility of flight cancellations, airspace closures and travel disruptions."