'Master bomb maker' behind latest terror threat
The FBI and CIA suspect that the upgraded version of the underwear bomb discovered by US intelligence officials in Yemen was designed by Ibrahim Hassan al-Asiri, or one of his proteges.
Al-Asiri is an al-Qaeda bomb maker believed to be responsible for the first underwear bomb used by a would-be suicide bomber on Christmas day in 2009 and for two devices built into printer cartridges shipped to the US on cargo planes in 2010.
In 2009 Umar Farouk Abdulmutallab boarded a plane to Detroit from Amsterdam on Christmas Day. He burnt his leg trying to ignite explosives on the plane which had 278 passengers and 11 crew on board.
The young Nigerian man said he was acting on behalf of al-Qaeda. He gave himself third-degree burns in the incident, but no one else was injured.
Prosecutors in his trial said the 80 grams of explosives the bomb contained could have caused mass destruction. They released this simulation video showing what could have occurred on the flight, had the device successfully detonated.
Al-Asiri is also thought to be responsible for the two packages that al-Qaeda built into printer cartridges and shipped to the US on cargo planes in 2010.
Both of the printer bombs contained a powerful industrial explosive, and both were viable when they were discovered at stop over routes. One at East Midlands Airport and one in Dubai.
The latest plot thwarted by the CIA involved an upgrade of the underwear bomb, with a more refined detonation system, according to US officials.
The FBI are still investigating whether the bomb could have passed through airport and brought down a plane.
They said the device did not contain metal; meaning it probably could have passed through an airport metal detector. It is not clear if the new body scanners used in many airports would have picked it up.
US Senator Dianne Feinstein, head of the Senate Intelligence Committee said she had been briefed about an "undetectable" device that was "going to be on a "US-bound airliner."
ITV News' Washington Correspondent Robert Moore reports that airports around the world will be reassessing the security measures they have in place.
The FBI and US Department of Homeland Security acknowledged the existence of the bomb, but there are no immediate plans to adjust security procedures at airports.