(Reuters) – Portland Police declared a gathering of protesters as a “riot” late on Sunday after saying its officers were attacked with lasers, rocks and bottles.

In a Twitter post, the police asked the gathering in the U.S. city’s North Precinct to disperse, adding that failure to comply with the order could lead to arrests and crowd control agents including tear gas and impact weapons.

Police had also declared a riot just before midnight on Saturday after a group of about 250 people – many of them wearing black and carrying shields, helmets and gas masks – tried to march on a government building that has often been the scene of violence during nearly three months of nightly protests.

Police made 14 arrests in that event.

Demonstrations against racism and police brutality have swept the United States since the death in May of George Floyd, a 46-year-old Black man who died after a Minneapolis police officer knelt on his neck for nearly nine minutes.

President Donald Trump’s administration in July deployed federal forces to deal with the protests in Portland.

On Friday, he denounced the demonstrations as “crazy” and said cities run by Democrats had descended into chaos. Portland Mayor Ted Wheeler is a Democrat.

Portland police said last week that they had declared riots 17 times between May 29 and Aug. 19.

(Reporting by Kanishka Singh in Bengaluru; Editing by Toby Chopra)