PORTLAND — A federal judge in Oregon on Monday rejected a defense request for a new trial for a young Somali American convicted in a terrorism case, finding that no serious miscarriage of justice occurred during his trial.

U.S. District Judge Garr King ruled on motions filed by lawyers for 21-year-old Mohamed Mohamud. The judge also rejected a defense motion to acquit the young man.

On Jan. 31, jurors found Mohamud guilty of attempting to detonate a bomb at Portland’s 2010 Christmas tree-lighting ceremony. The bomb was a fake, provided by government agents posing as terrorists.

“I conclude that no serious miscarriage of justice occurred during the trial, even when I view the issues raised by the defense cumulatively,” King said.

Mohamud’s chief lawyer could not immediately be reached for comment.