Almost 100 U.S. government personnel were evacuated from Yemen at dawn Tuesday as the State Department urged all Americans in the country to leave “immediately” because of an “extremely high” threat of a terrorist attack — even as a U.S. drone attack killed four suspected terrorists.
U.S. officials said the “non-emergency evacuation" of “just under a hundred” personnel was carried out by an US Air Force C-17 which took off from the Yemeni capital, Sana'a, bound for Ramstein air base in Germany. Some essential embassy staff stayed behind.
The operation to get people out happened as a U.S. drone strike killed four suspected al Qaeda members in the country.
A total of 19 U.S. embassies remained closed Tuesday after intelligence agencies intercepted an electronic communication between two of al Qaeda’s top leaders in which they agreed they “wanted to do something big” this past Sunday, according to sources.
Ayman al-Zawahiri, Osama bin Laden’s successor as the head of al Qaeda, and Nasir al-Wahishi, leader of Yemen-based al Qaeda in the Arabian Peninsula, wanted to time a significant attack to a Muslim holiday known as "The Night of Destiny," the day the Koran was revealed to Mohammed, the sources said.
In a statement Tuesday, the State Department said there was a “high security threat level in Yemen due to terrorist activities and civil unrest.”
“The department urges U.S. citizens to defer travel to Yemen and those U.S. citizens currently living in Yemen to depart immediately,” it said.
“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,” it added. “The security threat level in Yemen is extremely high.”
The statement noted that a mob had attacked the U.S. Embassy compound in September 2012 and a U.S. citizen was killed in Taiz in March 2012 with al Qaeda in the Arabian Peninsula claiming responsibility in the press.
The State Department also ordered a reduction in the number of "emergency U.S. government personnel in Yemen."
“The Department is taking appropriate steps to protect our employees, including local employees and visitors to our facilities,” State Department spokeswoman Jen Psaki said in a statement Tuesday.
Pentagon officials said a U.S. Air Force C-17 transport plane carrying some American government personnel had taken off from Yemen. They said the State Department had ordered non-essential personnel to leave the country.
An unknown number of U.S. Embassy personnel remain in Sanaa.
Pentagon Press Secretary George Little said the Defense Department "continues to have personnel on the ground in Yemen to support the U.S. State Department and monitor the security situation.”
The Ambassador to Yemen, Gerald Feierstein, is currently in Washington on a previously planned trip, a source familiar with his travel said.
Meanwhile, U.S. officials confirmed four militants were killed in an American drone strike Tuesday, but said none were considered to be in leadership positions. Yemeni tribal leaders told Reuters that the men were killed when five missiles struck a vehicle travelling in Maarib Province.
Yemeni authorities issued a statement early on Tuesday listing 25 "most wanted terrorists" that it said were planning to carry out attacks in the country.
The list included al Qaeda in the Arabian Peninsula's top bombmaker, Ibrahim Hassan al-Asiri. A reward of five million Yemeni riyals ($23,000) was offered for information leading to their capture.
Yemeni Foreign Minister Abu-Bakr al-Qirbi criticized the U.S. decision to get Americans out.
"Unfortunately, these measures, although they are taken to protect their citizens, in reality they serve the goals that the terrorist elements are seeking to achieve," Qirbi told Reuters. "Yemen had taken these threats seriously and had taken all the necessary measures to protect all the foreign missions in the country."
The U.S. Embassies in Yemen, Egypt, Saudi Arabia and Libya are among the 19 diplomatic posts that will remain closed until Aug. 10.
The U.K. said Tuesday it was withdrawing all its embassy staff from Yemen temporarily and “strongly” urged British citizens to leave immediately. “If you don’t leave the country now while commercial carriers are still flying it is extremely unlikely that the British government will be able to evacuate you or provide consular assistance,” it said in a statement.
AQAP has become the most sophisticated of the many al Qaeda affiliates. Operating mainly out of Yemen, it has attempted to carry out high-profile attacks on the U.S. and its interests overseas.
AQAP dispatched the so-called “underwear bomber,” Umar Farouk Abdulmutallab, who tried to detonate a bomb in an airplane over Detroit on Christmas Day 2009, and the terror group also launched a foiled plot to destroy U.S. cargo planes using a cartridge bomb.
However, NBC analyst Michael Leiter, former director of the National Counterterrorism Center, said experts both in and out of government that he had spoken to were “really scratching their heads” about seriousness with which Washington was taking the threat.
“I don't think this was purposeful hype, but no one who really knows al Qaeda or its history thinks that this is as huge a deal as portrayed -- and certainly nothing remotely close to the worst thing we have seen since 9/11,” he said.
“That is absurd hyperbole that is coming almost entirely from reckless commentators or ill-informed or ill-spoken Hill folks,” he added.
However Leiter added “all of that anti-hype being said, we have been wrong on stuff before.”
He said the apparent promotion of Yemen-based Wahishi to al Qaeda’s second-in-command “speaks volumes to what we have done in Afghanistan and Pakistan” and the importance of the terror network’s affiliate organizations to its cause.
NBC News' Robert Windrem, Matthew Cole, Catherine Chomiak and Richard Esposito, and Reuters contributed to this report.