Revealed: Bin Laden's successor ordered al Qaeda leader in Yemen to launch strike in 'biggest threat since 9/11' that closed 19 U.S. embassies across Muslim world

Intercepted: Ayman al-Zawahri, who was bin Laden's number two, ordered the head of al Qaeda in Yemen to launch the attack

The global terror alert that brought the closure of 19 U.S. embassies across the Muslim world was the result of a secret message the head of al Qaeda in Pakistan sent to his counterpart in Yemen ordering him to launch a strike, two security officials revealed today.
A U.S. intelligence official and a Mideast diplomat said electronic communications were picked up several weeks ago between Ayman al-Zawahri - the head of the global terror network who succeeded Osama bin Laden - and Nasser al-Wuhayshi, head of al Qaeda in the Arabian Peninsula.
Officials had previously called the communication 'strategically significant' and likened the intelligence 'chatter' to that intercepted in the days leading up to 9/11.
'This was significant because it was the big guys talking, and talking about very specific timing for an attack or attacks,' one American official briefed on the intelligence reports told the New York Times.
The news comes as the State Department extended the closure of 19 embassies and consulates across North Africa and the Middle East for the rest of the week amid fears of a 'big' and 'strategically significant' terrorist attack.
The two officials said the target has not been revealed but was significant in that it is extremely rare for senior al Qaeda leaders in Pakistan to discuss operational matters with the group’s affiliates.

Both officials spoke on condition of anonymity because they were not authorized to discuss the sensitive issue publicly.

Attack: Nasser al-Wuhayshi is the head of al Qaeda in the Arabian Peninsula and the development ties up with early reports of terrorist activity in Yemen

State Department officials said Thursday that they were taking action out of an 'abundance of caution' from the Arabian Peninsula

The U.S. State Department, based at the White House, Washington (pictured), has instructed its embassies and consulates in the Muslim word that would normally be open on Sunday to close this weekend amid reports of an unspecified threat

Threat: Senator Saxby Chambliss compares the chatter that led to a global terror warning to chatter intercepted before September 11

The identity of the two al Qaeda leaders helps to explain why the U.S. took such an unprecedented step closing 19 embassies and reflect the seriousness of the plot. It also raises questions about what form of electronic communication they used and are al Qaeda members increasingly using modern technology to communicate - especially considering bin Laden's aversion to cell phones.
Also the very fact they are communicating at all is also significant in that it shows the growth of the terror network.
American spies and intelligence analysts on Monday scoured email, phone calls and radio communications between al Qaeda operatives in Yemen and the organization's senior leaders to determine the timing and targets of the planned attack.

Authorities in Yemen, meanwhile, released the names of 25 wanted al Qaeda suspects and said those people had been planning terrorist attacks targeting 'foreign offices and organizations and Yemeni installations' in the capital Sanaa and other cities across the country.
The Yemeni government also went on high alert Monday, stepping up security at government facilities and checkpoints.
Officials in the U.S. wouldn't say who intercepted the initial suspect communications - the CIA, the National Security Agency, the Defense Intelligence Agency or one of the other intelligence agencies - that kicked off the sweeping pre-emptive closure of U.S. facilities.
But an intelligence official said the controversial NSA programs that gather data on American phone calls or track Internet communications with suspected terrorists played no part in detecting the initial tip.

Barriers block access to the U.S. embassy in Tel Aviv, Israel, on August 3

Boats are seen in front of the U.S. consulate building in Gulf emirate of Dubai, United Arab Emirates, on August 3

Once the plot was detected, NSA analysts could use the programs that leaker Edward Snowden revealed to determine whom the plotters may have contacted around the world. Snowden revealed one program that collected telephone data such as the numbers called and the duration of calls on U.S. telephone networks.
Another program searched global Internet usage. Therefore, if a new name was detected in the initial chatter, the name or phone number of that person could be run through the NSA databases to see whom he called or what websites or emails he visited.
The surveillance is part of the continuing effort to track the spread of al Qaeda from its birthplace in Afghanistan and Pakistan to countries where governments and security forces are weaker and less welcoming to the U.S. or harder for American counterterrorist forces to penetrate - such as Syria, Iraq, Somalia, Mali and Libya - as well as Yemen, already home to al-Qaida's most dangerous affiliate, al-Qaida in the Arabian Peninsula, which is headed by al-Wahishi.
Early reports indicated that the possible strike could involve a terrorist attack mounted by people with explosives surgically-implanted inside them - bombs capable of passing undetected through airport security.
On Sunday, Senator Saxby Chambliss of Georgia said 'the chatter' intercepted by U.S. intelligence agencies was 'very reminiscent of what we saw pre-9/11.'
'The one thing that we can talk about is the fact that there's been an awful lot of chatter out there,' Chambliss said. '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.'
ABC News reports that a senior American security source sayid officials are worried about explosive devices that can pass undetected through airport screening devices like metal detectors and body scanners.

'We are concerned about surgically implanted devices,' the source said.
'These are guys who have developed the techniques to defeat our detection methods.'
The State Department originally said the 19 U.S. embassies and consulates in the Middle east and North Africa would be closed through Saturday 'out of an abundance of caution' and that a number of them would have been closed anyway for most of the week due to the Eid celebration at the end of the Muslim holy month of Ramadan.
The diplomatic posts include those in Yemen, Libya, Egypt, Saudi Arabia and the United Arab Emirates.
Within the US the Department of Homeland Security has increased security at airports, train stations and transportation hubs. Security screening is also being increased into visitors coming into the country, officials told ABC News.
Representative C.A. Dutch Ruppersberger, the top Democrat on the House Permanent Select Committee on Intelligence, told ABC's 'This Week' on Sunday that the information intercepted from 'high-level people in al-Qaida in the Arabian Peninsula' included threats of a 'major attack.'

Closed: Bangladeshi police stop a motorist in front of the U.S. embassy building that remained closed due to security threat

'We’re not certain exactly where something might happen but it’s very specific as to when and it’s also very specific as to the fact that it is going to happen, so we have to be on alert everywhere,'  Rep. Peter King, chairman of the subcommittee on Counterterrorism and Intelligence, told WINS-AM. He said the threat is the 'most specific' he's seen since the 9/11 attacks.
'There's very little doubt that something serious is being planned,' King told CNN. 'It's a potential series of attacks. It could be anywhere.'
The U.S. issued a global travel alert for American travelers on Friday after intercepting electronic communication among top al Qaeda operatives in Yemen regarding an attack in its final planning stages. The al Qaeda affiliate in Yemen has been linked to plots to blow up American-bound cargo and commercial flights, according to the New York Times.
If traveling outside the U.S., King said: 'I would let the American embassy know where you are. Basically check in and where you are and how long you plan to stay there and what your itinerary is.'
State Department officials said Thursday that they were taking action out of an 'abundance of caution' after receiving information the terror group was in the final stages of planning for an unspecified attack.
The terror group and its affiliates 'may focus efforts to conduct attacks in the period between now and the end of August,' the State Department said.
Spokeswoman Marie Harf cited information indicating a threat to U.S. facilities overseas and said some diplomatic facilities may stay closed for more than a day.

Bangladeshi policemen stand guard outside the US embassy in Dhaka on Sunday

Police in Bangladesh check an auto-rickshaw passenger near the US embassy in Dhaka on Sunday

A source told CNN the preparations appeared to have increased in recent days with the approaching end of the Muslim holy month of Ramadan.
A U.S. official noted it was unclear whether the plot would be directed at a target inside Yemen or elsewhere.
Those officials spoke on condition of anonymity because they weren't authorized to speak publicly about the matter.
The British embassy in Yemen is to be closed on Sunday and Monday as 'a precautionary measure', the Foreign Office confirmed today.
On the heels of the American foreign travel alert, Interpol has issued a global security alert in connection with suspected al-Qaida involvement in several recent prison escapes including those in Iraq, Libya and Pakistan.
The Lyon, France-based international police agency said Saturday that the alert follows 'the escape of hundreds of terrorists and other criminals' from prisons in the past month. The alert calls on Interpol’s 190 member countries to help determine whether these events are coordinated or linked, the organization said.
On Sunday South Carolina Senator Lindsey Graham called the threat 'scary', saying al Qaeda has been 'on steroids' since the attacks on the U.S. consulate in Benghazi, Libya, last year.
He told CNN: 'I had a briefing with the vice president and it is scary. Al Qaeda is on the rise in this part of the world.
'They attacked our consulate, they killed an ambassador, a year has passed, and nobody has paid a price.
'After Benghazi, these al Qaeda types are really on steroids thinking we’re weaker and they’re stronger.'
The State Department issued a major warning last year informing American diplomatic facilities across the Muslim world about potential violence connected to the anniversary of the September 11 terrorist attacks.

The U.S. Embassy in Amman (pictured), the capital of Jordan, is among those which will close from Sunday as a 'precaution' following a reported terrorist threat

In Kabul, Afghanistan, where thousands of U.S. troops remain stationed, the U.S. Embassy (pictured) will also be closed this Sunday

Dozens of American installations were besieged by protest over an anti-Islam video made by an American resident.
In Benghazi, Libya, the U.S. ambassador and three other Americans were killed when militants assaulted a diplomatic post. The administration no longer says that attack was related to the demonstrations.
The United States is locking down its embassies and consulates throughout the Muslim world on Sunday after receiving an unspecified threat, officials said.

Quoted by ABC News, one official said the closures were a response to a 'specific threat against a U.S. embassy or consulate,' described as a 'concerted effort' to target an embassy or consulate in a Muslim country.
The official also said that 'there could be other targets, not just embassies'.

According to the news service, 28 U.S. installations will close Sunday, including  offices in Egypt, Iraq, Qatar, Bahrain, Kuwait, the United Arab Emirates and Oman.

The threat comes close to a year after four American consulate workers in Libya were killed in a night time arson attack.

The State Department issued a major warning last year informing American diplomatic facilities across the Muslim world about potential violence connected to the anniversary of the September 11 terrorist attacks.

President Barack Obama, pictured at the White House in January, paid his respects earlier this month to victims in Tanzania of the 1998 orchestrated terrorist attacks against several US embassies across the African continent

Dozens of American installations were besieged by protest over an anti-Islam video made by an American resident.

In Benghazi, Libya, the U.S. ambassador and three other Americans were killed when militants assaulted a diplomatic post.

An armed mob attacked and set fire to the consulate building in their protest against the amateur film - deemed offensive to Islam's prophet, Muhammad - after similar protests in Egypt's capital.

The administration no longer says that attack was related to the demonstrations.

The mass closure of U.S. embassies and consulates across the MENA region also comes almost 15 years ago to the day that hundreds of people were killed in simultaneous terrorist attacks, conducted by al Qaeda, on U.S. embassies in Nairobi, Kenya and Dar es Salaam.

In Dar es Salaam, 10 Tanzanians were killed and more than 85 Americans and Tanzanians were injured. The blast at the U.S. embassy in Nairobi killed at least 212 people and wounded an estimated 4,000.

In his recent visit to Africa, U.S. President Barack Obama paid his respects to those who lost their lives in the attacks.
In Britain, the Foreign Office said it was not shutting any embassies but has urged its staff in the Middle East and in Arab states to be vigilant.
'US Embassies in the region have been instructed to close on Sunday August 4. The British Embassies remain open, but staff have been advised to exercise extra vigilance as we approach Eid,' a spokesman said.
‘We are aware of reports and are in close contact with the US authorities. We will consider every Embassy on case by case basis; clearly the safety of our staff overseas is our highest priority.
'Our travel advice remains under constant review. We are not going to comment on intelligence matters.
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