By F. Brinley Bruton, Staff Writer, NBC News
International police agency Interpol announced a global security alert advising its members to be more vigilant about possible terror attacks just days after the 
United States also issued a travel alert and closed 21 embassies worldwide.
Interpol linked its warnings to a series of prison breaks in Iraq, Libya and Pakistan.
“With suspected al Qaeda involvement in several of the breakouts which led to the escape of hundreds of terrorists and other criminals, the Interpol alert requests the organization’s 190 member countries’ assistance in order to determine whether any of these recent events are coordinated or linked,” the France-based organization said in a statement issued on Saturday.
NBC News counter-terrorism analyst Michael Leiter and NBC’s Richard Engel join Lester Holt with more on the al Qaeda threat.
In addition to the recent prison breaks, Interpol pointed to other possible reasons for the heightened security fears. August is the anniversary of deadly attacks in Mumbai, India, and Gluboky, Russia, as well as in Jakarta, Indonesia. The week of Aug. 3 is also the 15th anniversary of the bombings of American embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania, in which more than 200 were killed some 4,000 injured.
More than 20 U.S. embassies and consulates that normally open on Sundays — mostly in the Muslim world — were closing this weekend because of the potential threat.
On Saturday evening, Susan Rice chaired a National Security Council meeting at the White House to discuss the latest intelligence regarding a possible al Qaeda attack.
There are different views among analysts — including whether a plot is already underway, with team members already selected, as reported Saturday by CBS.
At least some present at the meeting said they believed that to be the case, but others disagree. There is no consensus on whether the plot is underway, officials told NBC News.
The threat of an al Qaeda attack is “real and serious” and “we must not let our guard down,” the chairman of the House Permanent Select Committee on Intelligence warned on Friday after a worldwide alert was issued for all U.S. citizens traveling abroad.
The State Department warned the terror group and its affiliates “may focus efforts to conduct attacks in the period between now and the end of August.”
“The Department of State alerts U.S. citizens to the continued potential for terrorist attacks, particularly in the Middle East and North Africa, and possibly occurring in or emanating from the Arabian Peninsula,” it added.
The travel alert expires on August 31.
Britain has confirmed it was also closing its embassy in Yemen on Sunday and Monday, and France said it was shuttering its embassy in the country for a few days.
Tony Capra, Andrea Mitchell and Catherine Chomiak, NBC News, and Reuters contributed to this report.