The United States says 19 of its diplomatic missions in the Middle East and Africa will remain closed for the rest of the week, even as it reopened some of its embassies on Monday.
While embassies in Kabul and Baghdad were reopened, 19 diplomatic missions will remain shut through Saturday because of security concerns.
Deputy State Department Spokesperson Marie Harf said the decision was made after a post-by-post analysis.
"We continue to refine our assessment of the threat. We continue, as you can imagine, to get new information, and, as we do so, we'll evaluate our security needs going forward," said Harf.
Some missions - like the U.S. embassy in Cairo - usually serve a large number of American tourists. Those numbers have shrunk but the State Department says Americans and foreigners who need to get in touch with U.S. missions while abroad this week can go online for contact information.
Harf said the closures were not a matter of choice.
"Our preference, I should say here, is for embassies and consulates to be open. Clearly, we operate around the world in places like this because we have a mission there," said Harf.
U.S. officials have said attacks could emanate from the Arabian peninsula where the Yemen-based al-Qaida affiliate seems determined to attack Western interests. The U..S embassy in Sana’a, Yemen's capital, remains closed.
News reports say the embassy closures were prompted by intercepted communications between al-Qaida chief Ayman al Zawahiri in Pakistan and the head of al-Qaida in the Arabian Peninsula. Specific targets apparently were not specified.
Former U.S. Ambassador James Jeffrey, who is now at the Washington Institute for Near East Policy, says intercepted communications are hard to analyze.
"It's coded language. It's language that talks around the subject. There's increases in chatter. There's all kinds of other things to lead analysts to figure out they're going to hit something big and it's going to involve the United States," says Jeffrey.
In Sana’a, Britain, France, Germany and Norway are also keeping their embassies closed until later in the week.
The Middle East Institute's Graeme Bannerman says embassy threats in a volatile region like the Middle East must be taken seriously.
"You, as a diplomatic security person, want to close the embassy down. Period. I mean, that's what you have to do just because you cannot take the chance that something awful could happen."
Analysts say that while the threat of an attack sometimes could interfere with consular services, at the end of the day, inconvenience is a better option than loss of life.