Specific threats to Western targets in Muslim countries have prompted the closure of a number of U.S. embassies and consulates after a terroristic threat made by an al Qaeda branch was deemed active and credible, U.S. officials said.
The threat, made by al Qaeda fighters in the Arab Peninsula, has forced 21 embassies spanning 5,000 miles from Algeria to Bangladesh, to close their doors on Sunday.
Officials intercepted electronic communications this week between senior al Qaeda leaders in which they discussed attacks in the Middle East and Northern Africa, according to a senior U.S. official in the region.
"It is more specific and we are taking it seriously, which I think you'd expect us to do," Joint Chiefs of Staff Chairman Gen. Martin Dempsy told ABC News during the interview for "This Week." "There is a significant threat stream and we're reacting to it."
In Cairo, the U.S. embassy has been barricaded by stone as approximately 500 marines across the region are prepared to respond to any attack.
In addition, the U.S. has issued a global travel warning to citizens around the world out of fear of the attacks, urging Americans to be alert 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."
A U.S. official told ABC News the threat is believed to center around Yemen, but there are indications it could be a broader plot that could involve multiple targets.
"Current information suggests that al Qaeda and affiliated organizations continue to plan terrorist attacks both in the region and beyond, and that they may focus efforts to conduct attacks in the period between now and the end of August," the State Department warning said.
The State Department said that "terrorists may elect to use a variety of means and weapons and target both official and private interests," and reminds U.S. citizens of potential targets such as public transportation and tourist sites, and to take precautions.
"Terrorists have targeted and attacked subway and rail systems, as well as aviation and maritime services," according to the statement.
In Yemen, the likely targets are "where there is a U.S. presence" in the capital of Sanaa, a U.S. official said, which would mean the U.S. embassy and the Sheraton Hotel where many U.S. citizens are located.
The official said the State Department, which was shaken following the attack in Benghazi, Libya, that killed the U.S. ambassador in September 2012, decided to broaden the response and close embassies elsewhere as well.
"We continue to work closely with other nations on the threat from international terrorism, including from al Qaeda. Information is routinely shared between the U.S. and our key partners in order to disrupt terrorist plotting, identify and take action against potential operatives, and strengthen our defenses against potential threats."