THE FBI HAS ARRESTED a Somali-born teenager who was allegedly plotting to explode a car bomb in Oregon.

US authorities believe Mohamed Osman Mohamud, 19, planned to detonate the bomb during a Christmas lighting ceremony in Portland.

Bloomberg reports that the FBI said in a statement that Mohamud was arrested after attempting to “detonate what he believed to be an explosives-laden van”.

The device was actually a fake supplied by undercover agents, according to Al Jazeera. The sting operation began in June when agents allegedly discovered a link between Mohamud and an associate in northwest Pakistan.

Undercover FBI agents met with Mohamud and he told them he had identified the Portland ceremony was a potential target.

The FBI claims he went ahead with his plan despite being provided a number of opportunities to stop. Haaertz reports that the teenager was arrested shortly before the Christmas ceremony was due to take place.

Mohamud, a naturalised US citizen, is due to appear in court on Monday. He could face life in prison and a $250,000 fine if convicted of attempting to use a weapon of mass destruction.

Just under a year ago, a Nigerian man was charged with attempting to blow up a plane in Detroit. The man had been overpowered by passengers and flight crew on board the transatlantic jet when he tried to detonate the device.