Investigators examining explosives found in packages intercepted in Britain and Dubai suspect the material, preliminarily identified as PETN, points not only to the role of an al-Qaeda affiliate in Yemen but to a sophisticated bomb-maker who last year sent his brother to his death in an effort to kill a Saudi prince.
Ibrahim Hassan al-Asiri, a 28-year-old Saudi national who is on that country's most-wanted list, secreted a PETN-based bomb in a body cavity of his younger brother, Abdullah, who pretended to be turning himself in. The bomb killed his brother and wounded Mohammed bin Nayef, a top counterterrorism official and Saudi royal.
Asiri, who is based in Yemen, is also believed to have built the underwear bomb that a Nigerian man trained in Yemen attempted to detonate last Christmas Day on a commercial aircraft approaching Detroit. That device also contained PETN, or pentaerythritol trinitrate. "He is certainly someone we are focused on," a U.S. official said of Asiri.
Both packages were shipped from Yemen, where officials said Saturday that they had arrested a woman suspected of mailing them. Yemeni President Ali Abdullah Saleh told reporters in the capital, Sanaa, that the United States and the United Arab Emirates had provided information that helped identify the woman, who was arrested at her home in Sanaa. Yemeni officials told the Reuters news agency that the woman, who was not named, is a medical student in her 20s.
A British minister said Saturday that the bomb, found in a package destined for a Chicago synagogue, was "viable," and could have exploded and brought down the UPS plane that was carrying it. "We do not believe that the perpetrators of the attack would have known the location of the device when they planned for it to explode," said British Home Secretary Theresa May. That suggests the device could have exploded automatically rather than be detonated remotely.
Officials, however, declined to describe the trigger mechanism, and noted that a forensic investigation continues. A second package was found at a FedEx facility in Dubai, and authorities there said the device, skillfully built inside a printer cartridge, contained an electric circuit and a cellphone chip. The powerful devices were designed to beat airport scanners, officials said. "The targeting manner carries characteristics similar to methods previously carried out by terrorist organizations like al-Qaeda," authorities in Dubai said in a statement. U.S. officials said the packages were intercepted following a tip from intelligence officials in Saudi Arabia.
An official from a country involved in the investigation said the Saudis first warned the United States that dangerous packages had just left Yemen, and that officials in several countries then reacted with great speed. The official contrasted that with the investigation of the Christmas Day bombing, in which communications failed at numerous levels. The White House said that President Obama called Saudi King Abdullah Saturday to thank him for his country's "critical role" in breaking up the plot.
The president also spoke to British Prime Minister David Cameron. Speaking to reporters at his country residence outside London, Cameron said: "We believe the device was designed to go off on the aeroplane. We cannot be sure about the timing when that was meant to take place." Both packages were addressed to synagogues in Chicago. U.S. officials said they were not yet certain where the bombs were designed to explode or whether the synagogues were, in fact, the intended targets.
U.S. officials said they also didn't know whether the synagogues were chosen because they are located in Obama's hometown, or how they were selected at all. A number of U.S. citizens hold prominent roles in Al-Qaeda in the Arabian Peninsula, or AQAP, including the American-born cleric Anwar al-Aulaqi, a leading ideologist and operational planner. The group has proven to be very media-savvy, producing an online English-language magazine called "Inspire" and uploading video with English subtitles to YouTube.
The al-Qaeda affiliate in Yemen is largely autonomous from the group's central leadership, now believed to be headquartered in the lawless tribal region of Pakistan near the Afghan border, when it comes to making operational decisions. U.S. officials said the Yemeni group is viewed as an increasingly potent threat, open to all tactics in order to strike a blow against the United States.
Since the attempted Christmas Day bombing, the U.S. has announced it will significantly increase military aid to a government that does not control large tracts of its own country. In addition to the threat from al-Qaeda in the Arabian Peninsula, Yemen's weak central government is dealing with a secessionist movement in the south of the country and a civil war against Shiite rebels in the north U.S. officials have debated whether to deploy armed CIA drones to the country, but Saleh, in a brief news conference Saturday, rejected any foreign intervention
. "We do not want anyone to interfere in Yemeni affairs by hunting down al-Qaeda," said Saleh, whose 32-year-long rule has been marked by authoritarianism and human rights abuses, according to Western groups such as Human Rights Watch. Authorities in Yemen said Saturday that they continued to search for other suspicious packages. A U.S. law enforcement official said authorities here now believe they have identified and cleared all packages mailed from Yemen in the same period as the bombs.
The U.S. Postal Service announced Saturday that it has temporarily suspended acceptance of inbound international mail originating in Yemen. Britain and France also suspended air freight from YemenHomeland Security Secretary Janet Napolitano said on CBS's "Early Show" Saturday morning that the "plot does have the hallmarks" of an attack by al-Qaeda in the Arabian Peninsula. She also said on CNN that the parcel bombs appeared to contain PETN.
We know aviation continues to be a target, we know the system continues to be looked at by our adversaries," said Napolitano. Current and former officials who have worked with explosives said the bomb-makers showed skill at their task. "There is some sophistication, as far as the knowledge of being able to put it together," said David Williams, a retired FBI agent and explosives expert who investigated the first World Trade Center bombing in 1993.
He said the PETN explosive was probably stripped out of a commercial product like a detonating cord. But it is also possible the bombers made a batch of PETN themselves, said Williams, who now runs the International Counter Terrorism Consulting Group, based in Harwood, Md. "If you could make moonshine, you could make PETN," he added, noting it involved distillation, the combination of various chemicals, and a chilling process.
One federal law-enforcement official said the bomb-maker could have obtained the PETN from a government munitions program or a mining company, or could have figured out how to manufacture it. Richard Reid, the British "shoe bomber," also carried a device made with PETN when he attempted to bring down a flight from Paris to Miami in December 2001. Williams said the latest bombs sent from Yemen differed from the device carried by Umar Farouk Abdulmutallab, the alleged "underwear bomber," because they used electronics rather than a chemical reaction to detonate the explosives.
The mail bombs had circuit boards, and a cellphone battery could have been the power source for the blast, Williams said. If al-Qaeda is the culprit, it appears to be the first time the group has attempted to use the mail to deliver an explosive, Williams said. "It seems like a logical progression," he added, saying the bomb-makers figured out that there was less screening of packages than of passengers.
