The United States and Britain evacuated their embassies in Yemen Tuesday and advised all their citizens to leave the country as soon as possible due to heightened security risks.
"The US Department of State warns US citizens of the high security threat level in Yemen due to terrorist activities and civil unrest," said an advisory posted on its website. "The Department urges US citizens to defer travel to Yemen and those US citizens currently living in Yemen to depart immediately."
All non-emergency government employees have been ordered to leave, the notice said, citing "the continued potential for terrorist attacks."
A State Department representative said at a Tuesday press conference that actions in Yemen were made in response to a "specific, immediate threat."
But US State Department spokeswoman Jen Psaki told reporters on Tuesday that it is "inaccurate to call it an evacuation."
"This is a reduction in staff," she said, adding that operations have been suspended. "Although," the Guardian observed, "the embassy is closed."
"Our focus is on keeping both our personnel and citizens who are traveling overseas safe," Psaki explained, saying US Secretary of State John Kerry spoke with Yemeni president Hadi about the situation last night.
A US military cargo plane flew embassy staff out of Yemen early Tuesday morning, US officials told ABC News. According to NBC News, almost 100 American government personnel were evacuated from the country.
The UK Foreign Office on Tuesday announced that it, too, had evacuated its embassy and urged all Britons to "leave now."
More from GlobalPost: Al Qaeda plot allegedly behind embassy closures
The US Embassy in the Yemeni capital, Sanaa, was one of 21 across Africa, Asia and the Middle East ordered to close on Sunday, and 19 told to remain shut through the week. The United Kingdom, Germany and France also advised their missions in Yemen to close temporarily.
Until now, US officials had described the move as a precautionary measure; but on Tuesday, the State Department described the security threat level in Yemen as "extremely high."
The alert is believed to have been sparked by "chatter" between senior Al Qaeda militants that indicated a terrorist attack was planned.
Al Qaeda leader Ayman al-Zawahiri was reportedly overheard talking with Amir Nasser al-Wuhayshi, a co-founder of the Yemen-based Al Qaeda in the Arabian Peninsula (AQAP), about imminent attacks against US targets, the New York Times reported Monday.
Earlier on Tuesday, Yemeni officials said that at least four people were killed in a US drone strike in Maarib province, central Yemen. The targets were suspected Al Qaeda militants, tribal leaders told Reuters.
Also on Tuesday, tribesman reportedly shot down a Yemeni army helicopter. According to witnesses, the chopper was firing on gunmen accused of blowing up an oil pipeline. The Associated Press, citing the Yemen government, said all eight people aboard were killed.
The Yemeni government also released a list of 25 terrorists it believes are planning to carry out attacks during Muslims' Eid al-Fitr holiday this week, Reuters said.
Intelligence agencies report that Al Qaeda members from throughout the region have arrived in Sanaa in recent days, one security source told the BBC, fueling fears that an attack is on its way.
Authorities have ordered "unprecedented" security measures across the capital, the BBC's correspondent said.