Law enforcement declared an unlawful assembly late Saturday, forcing protesters from downtown Portland, Oregon, and making several arrests, just hours after demonstrations earlier in the day ended without many reports of violence.

Hundreds of people were gathered downtown in Oregon’s largest city when the unlawful assembly was announced just before midnight by the Multnomah County Sheriff’s Office.

Images showed protesters crowded in and around a park near the Mark O. Hatfield United States Courthouse — the same courthouse that had been the scene of nightly unrest over the summer. A protester was seen burning an American flag.

Earlier, protesters had shot fireworks at police. Video posted by KOIN-TV showed officers warn that protesters who hurl projectiles will be subject to arrest.

Several arrests were made, according to reporters at the scene, but a specific number was not immediately available.

The unrest came just hours after a right-wing rally and counterprotesters largely dispersed without serious violence. Although, police were investigating an assault after one person who was documenting the event was pushed to the ground and kicked in the face.

Separately, police said a criminal citation was issued after officials confiscated firearms, paintball guns, baseball bats and shields from a pick-up truck that was initially stopped for having obscured license plates as it left the rally.

Oregon State Police Superintendent Travis Hampton and Multnomah County Sheriff Mike Reese praised the minimal violence in a joint statement late Saturday.

“Our Unified Command worked well to prevent violence before it started,” Hampton said in the statement. “Law enforcement officers performed a number of traffic stops and took weapons off the streets.”

“On Saturday, Oregonians denounced hate, racism and violence,” Reese stated, adding that, “the Unified Command was able to help keep the peace.”

Several hundred people, dozens of them wearing militarized body armor, gathered to support President Donald Trump and his “law and order” reelection campaign Saturday afternoon. The attendance was far fewer than the 10,000 organizers had expected after tensions boiled over nationwide following the decision not to charge officers in Louisville, Kentucky, for killing Breonna Taylor.

Organized by the Proud Boys, a group that has been designated as a hate group by the Southern Poverty Law Center, the rally was described as a free speech event to support Trump and police and condemn anti-fascists and “violent gangs of rioting felons” in the streets.

Local and state elected officials condemned the event and rushed to shore up law enforcement ranks as left-wing groups organized several rallies to oppose the Proud Boys’ message. About 1,000 counter-protesters gathered at another park.

The events began at noon and were largely dispersed by 3 p.m.

The rally came as Portland has seen nearly nightly protests since the police killing of George Floyd in late May.