While the United States successfully disabled Al-Qaeda from Afghanistan in the aftermath of 9 /11; the terrorist organisation and its offshoots are rebuilding in Pakistan, Yemen and Africa, a top American intelligence official has said.
"While we disabled Al-Qaeda's training and financing mechanisms in Afghanistan in the wake of the September 11 attacks, it is clear that Al-Qaeda and its offshoots are rebuilding in Pakistan, Yemen, and the Horn of Africa," Robert S Mueller, Director Federal Bureau of Investigation (FBI), said on Wednesday.
Appearing before a Congressional Committee, Mueller said US also face threats from homegrown extremists, those who live in the communities they intend to attack, and are often self radicalised and self trained.
"We also face threats from individuals who travel abroad to terrorists training camps in order to commit acts of terrorism overseas or to return home to attack America.
And these threats continue to change and evolve as extremists are now operating in new sanctuaries around the world, as Al-Qaeda and its offshoots are rebuilding in Pakistan, Yemen and the Horn of Africa," he said in his testimony before the Senate Judiciary Committee.
"While the terrorist threat has not diminished, together with our intelligence community partners, we have disrupted a number of plots over the past year.
We have learned a great deal from these cases, both about the new emerging threats and how to stop them," he said.
Giving details, Muller said in May, four individuals in New York -- some of whom met and were radicalised in prison -- were arrested for plotting to blow up Jewish synagogues and to shoot down military planes.
In July, a group of heavily armed extremists in North Carolina were arrested for making plans to wage jihad overseas after traveling to terrorists training camps, he said.
In September, on the eve of September 11, a Colorado resident was arrested in New York for planning to set off a bomb after having received detailed bomb-making instructions from Pakistan, the FBI Director said.
That same month, two self radicalised loners, one in Springfield, Illinois and one in Dallas, Texas, were arrested for attempting to bomb a federal courthouse and a downtown office tower in those respective cities, he said.
"Weeks later, a Chicago resident was arrested for his role in planning a terrorist attack in Denmark and assisting in the deadly 2008 Mumbai attacks.
And, of course, the killing of a young Army recruiter in Arkansas in May and the tragic shootings at Fort Hood in November are stark examples where lone extremists have struck the military here at home," Mueller said.
"Last year's cases demonstrate the diversity of new threats we face, some involve self radicalised terrorists influenced by the Internet or their time in prison, others receive training or guidance from known terrorists organisations abroad, either in person or over the Internet.
And the targets of these attacks range from civilians to government facilities to transportation infrastructure and to the military both in the United States and overseas," he said.
"On Christmas Day, the attempted bombing of Northwest Flight 253 has made it clear that the threat of attack from Al-Qaeda and its affiliates continues to this day and we can and must do more in response to these threats," he said.