(WASHINGTON) -- The U.S. State Department has ordered the evacuation of all non-essential personnel from Yemen because of an increased terror threat. A U.S. military cargo plane assisted with the evacuation early Tuesday morning, U.S. officials told ABC News.
"We are concerned about a threat stream indicating the potential for terrorist attacks against U.S. persons or facilities overseas, especially emanating from the Arabian Peninsula," State Department spokeswoman Jen Psaki said in a statement. "The Department is taking appropriate steps to protect our employees, including local employees and visitors to our facilities."
The order includes a reduction of emergency staff from the embassy as well, although a small number of emergency staff will stay. The U.S. ambassador to Yemen, Gerald Feierstein, is in Washington.
Pentagon press secretary George Little confirmed in a statement that the Defense Department will continue "to have personnel on the ground in Yemen to support the U.S. State Department and monitor the security situation."
The State Department on Tuesday also urged Americans in the country to "leave immediately" because of the "continued potential for terrorist attacks."
An emergency message to U.S. citizens posted on the U.S. Embassy in Yemen's website Tuesday described the terror threat as "extremely high."
"U.S. citizens currently in Yemen should depart," the message reads. "As staff levels at the Embassy are restricted, our ability to assist U.S. citizens in an emergency and provide routine consular services remains limited and may be further constrained by the fluid security situation."
The State Department issued a worldwide travel alert last week that shut down nearly two dozen U.S. embassies and consulates in the Middle East and Africa after conversations were intercepted between two al Qaeda leaders suggesting an impending terror attack.
The State Department had initially said the closures were "out of an abundance of caution" but the travel alert expires at the end of August and advised that al Qaeda continues to plan "terrorist attacks both in the region and beyond."
"The U.S. government remains highly concerned about possible attacks on U.S. citizens (whether visiting or residing in Yemen), and U.S. facilities, businesses and perceived U.S. and Western interests," the alert read.
The BBC reported on Tuesday that security is "unprecedented" in Yemen's capital, Sana'a, with "hundreds of armored military vehicles" deployed around key infrastructure buildings and Western embassies.
The U.K. Foreign Office announced on Tuesday that it is evacuating all British staff out of Yemen.
"Due to increased security concerns, all staff in the British Embassy have been temporarily withdrawn and the Embassy will remain closed until staff are able to return," the statement read.
The U.S. Embassy in Sana'a is scheduled to remain closed until Saturday, along with 18 other embassies across the Arab world.
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