WASHINGTON -- Nineteen American diplomatic outposts across the Middle East and North Africa will remain closed this week, the State Department said Sunday, despite what officials said was no new information about terrorist plots that they believe are in the works.
One day after President Obama's top national security aides huddled at the White House, senior lawmakers appeared on television on Sunday with ominous warnings about intelligence "chatter," first revealed on Thursday, similar to what American spy agencies picked up in the weeks before the attacks of Sept. 11, 2001.
Such is the strange, wait-and-see climate surrounding a threat that appears to be both specific and maddeningly vague. American officials say that they are confident they have intercepted electronic communications discussing attacks in the coming days, but that they have no clear information about where they should try to defend against them.
"The assumption is that it's probably most likely to happen in the Middle East," said Representative Peter T. King, Republican of New York, on the ABC News program "This Week." "But there's no guarantee of that at all."
"It could basically be in Europe, it could be in the United States, it could be a series of combined attacks," said Mr. King, who is a member of the House Intelligence Committee.
The one aspect of the intelligence that officials appear to agree on is that Al Qaeda's affiliate in Yemen is behind the plotting.
The group, Al Qaeda in the Arabian Peninsula, has tried to carry out several high-profile attacks in recent years. One was a man's attempt to blow up a trans-Atlantic jet over Detroit on Dec. 25, 2009, using explosives sewn into his underwear. Months earlier, the group tried to kill the Saudi intelligence chief with a bomb surgically implanted in the attacker's body.
American officials believe that both bombs were built by Ibrahim al-Asiri, one of the group's leaders whom the Obama administration has been trying to kill as part of a campaign in Yemen using armed drones.
The State Department said Sunday that it was extending the closing of 19 diplomatic posts in the Middle East and North Africa through at least next Saturday because of continued fears of an imminent attack. Several European countries have also closed embassies in the Middle East.
A State Department spokesman said that the closings were not the result of new threat intelligence, but "merely an indication of our commitment to exercise caution and take appropriate steps to protect our employees and visitors to our facilities."
The embassies that will be closed include ones in Yemen, Libya, Egypt, Saudi Arabia and the United Arab Emirates, the statement said.
Seth G. Jones, a terrorism expert at the RAND Corporation, said that the scope of the closings is a sign of how diffuse the terrorist threat has become, and how difficult it is to guard against.
"The U.S. has to deal with a number of terror groups across multiple continents who are generally not coordinating with each other," Mr. Jones said.
"This is the new Al Qaeda. It is better understood as a loose movement, rather than a single organization."
Senior lawmakers from both parties said Sunday that the embassy closings appeared justified. Senator Richard J. Durbin, the Illinois Democrat, said that the intelligence information added up to "a big deal." He said on the NBC News program "Meet the Press" that Vice President Joseph R. Biden Jr. gave members of Congress of classified briefing last week indicating that about 25 American embassies around the world were vulnerable.
Saxby Chambliss, the Georgia Republican who is the ranking member of the Senate Intelligence Committee, said the threat information was "very reminiscent of what we saw pre-9/11."
"We didn't take heed on 9/11 in a way that we should, but here I think it's very important that we do take the right kind of planning as we come to the close of Ramadan," said Mr. Chambliss, referring to the Islamic holy month, on "Meet the Press."
Lawmakers on Sunday gave credit for unmasking the threat to the National Security Agency, which has come under criticism after revelations about its extensive electronic monitoring programs in the United States and abroad.
In the days immediately after the N.S.A. revelations began, some American officials warned that terrorist leaders had already changed their communication methods and patterns of as a result of the exposure the revelations had brought. But the N.S.A.'s ability to intercept the recent discussions about plots seems to indicate that American spy agencies have not been hindered as much as some have asserted.
Senator Durbin indicated that what is perhaps the most contentious of the recent N.S.A. disclosures -- a program to gather and store phone records of all calls made inside the United States -- is not responsible for unearthing the recent plotting.
"In other words, do we need to collect all of the phone records of all of the people living in America for five years so that if we're going to target one particular person, we're ready to jump on it?" he said.
"That is being discussed and debated."
Brian Knowlton contributed reporting.
This article originally appeared in The New York Times.