|Somali-born Mohamud Osman Mohamud is a naturalised US citizen
A planned car bomb attack on a Christmas tree lighting ceremony in the US state of Oregon has been thwarted after a sting operation, law enforcement agencies have said.
Somali-born Mohamed Osman Mohamud was arrested on Friday afternoon after he dialled a mobile phone that he thought would blow up a van laden with explosives in the city of Portland.
However, the device was an imitation supplied by undercover agents and the call prompted federal official and local police to move in to arrest 19-year-old Mohamud, police said.
"The complaint alleges that Mohamud attempted to detonate what he believed to be a vehicle bomb at a crowded holiday event in downtown Portland, but a co-ordinated undercover law enforcement action was able to thwart his efforts and ensure no one was harmed," David Kris, the assistant attorney general for national security, said.
"While the public was never in danger from the device, this case serves as yet another reminder of the need for continued vigilance both at home and abroad."
Federal court documents show the sting operation began in June after an undercover agent learned that Mohamud had been in contact with an "unindicted associate" in northwest Pakistan.
The alleged accomplice is said to have referred Mohamud to a second conspirator overseas and provided him with a name and email address to facilitate the plot, according to the documents.
In the months that followed, Mohamud allegedly made several unsuccessful attempts to contact his partner before, last June, an FBI undercover operative contacted Mohamud via email under the guise of being an associate of his Pakistani contact.
Mohamud and the FBI undercover operative then agreed to meet in Portland in July, where the 19-year-old allegedly told the agent that he had written articles that were published in "Jihad Recollections," an online magazine that advocated violence against non-Muslims.
He later told undercover FBI operatives that he had identified the annual Christmas tree lighting ceremony in Portland's Pioneer Courthouse Square on November 26, 2010 as a potential target, according to the documents.
FBI operatives cautioned Mohamud about the seriousness of this plan, noting that there would be many children at the event, but Mohamud responded that he was looking for a "huge mass that will ... be attacked in their own element with their families celebrating the holidays," the affidavit said.
Mohamud, who is a naturalised US citizen, is expected to make his initial appearance in federal court in Portland on Monday.
"This defendant's chilling determination is a stark reminder that there are people - even here in Oregon - who are determined to kill Americans," Dwight C. Holton, the US attorney for the District of Oregon, said.
"The good work of law enforcement protected Oregonians in this case and we have no reason to believe there is any continuing threat arising from this case.”
Mohamud faces a maximum statutory life sentence and a $250,000 fine if convicted of the charge of attempting to use a weapon of mass destruction.
The US Senate Homeland and Governmental Affairs Committee warned in March 2009 that there was an increasing threat of attacks by radicalised Somali-Americans.
"Over the last two years, individuals from the Somali community in the United States, including American citizens, have left for Somalia to support and in some cases fight on behalf of al-Shabaab," Joseph Lieberman, the Committee's chairman, said referring to an armed group trying to topple the somali government.
The Committee said that deeply isolated and and alienated members of the community were being recruited to carry out attacks either at home or abroad.