A 19-year-old Somali-American man has pleaded not guilty to an alleged plot to blow up a car bomb at an Oregon Christmas tree lighting ceremony in Portland.

Mohamed Osman Mohamud entered the plea Monday in federal court in Portland.

An indictment filed earlier in the day charged him with attempted use of a weapon of mass destruction.

Mohamud was arrested Friday evening near the crowded Pioneer Courthouse Square in downtown Portland, amid an FBI sting operation that followed months of investigation.

A judge set a tentative trial date for Feb. 1.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

PORTLAND, Ore. (AP) — A 19-year-old Somali-American man was indicted Monday on federal charges that he tried to blow up a car bomb at a Christmas tree lighting ceremony in downtown Portland.

The indictment charged Mohamed Osman Mohamud with attempted use of a weapon of mass destruction. He was arrested Friday evening near the crowded Pioneer Courthouse Square, after a months-long FBI sting operation.

Dozens of people — many of them women wearing head scarves — arrived at the federal court building where Mohamud was scheduled for a court hearing. One of them, Mujahid El-Naser, said he attended middle school in Portland with Mohamud and that he didn't believe his friend would have gotten involved in the plot without encouragement of the FBI.

Mohamud was arrested after he and an agent drove into downtown Portland in a white van that carried six 55-gallon drums with detonation cords and plastic caps, but all of them were inert. Authorities said they allowed the plot to proceed to obtain evidence to charge the suspect.

"If you talk with someone enough, they'll be convinced they need to do something. That what's I think the FBI might have done with him," said El-Naser.

He added that he never heard his friend express any extremist views.

Isgow Mohamed, the director of the Northwest Somali Community Organization who also attended the hearing, said the allegations were surprising.

"This is not what we were expecting from him because he's a good man who went to college," he said of Mohamud, who had recently dropped out of Oregon State University. "He was expecting a good life."

Mohamud's attorney, Stephen R. Sady, who has represented terrorism suspects held at the U.S. prison at Guantanamo Bay, didn't return a telephone message left Sunday by The Associated Press.