Sept 7 (Reuters) - Police arrested another 15 people in Portland after protests were held overnight on Sunday near a police precinct as the Oregon city has crossed 100 days of demonstrations that have at times turned violent.
Protesters set fire on some mattresses that were put out eventually by firefighters, Portland police said in a statement.
The police said there were no injuries, adding they arrested 15 people on charges like interfering with a peace officer, disorderly conduct, possession of a dangerous device and reckless burning.
The development came a night after Portland police arrested 59 people and used tear gas late on Saturday as protesters threw rocks and fire bombs at officers.
Portland has seen nightly protests for over three months that have at times turned into violent clashes between demonstrators and officers, as well as between right- and left-wing groups.
Demonstrations erupted around the United States following the death in May of George Floyd, a Black man, after a Minneapolis police officer knelt on his neck for nearly nine minutes.
President Donald Trump signed a memo on Wednesday that threatens to cut federal funding to "lawless" cities, including Portland. His Democratic challenger in the Nov. 3 presidential election, Joe Biden, has accused Trump of stoking violence with his rhetoric.
(Reporting by Kanishka Singh in Bengaluru)