CLEVELAND — Protesters burned an American flag and mixed it up with police on Wednesday in the first notable demonstration outside the Republican convention. Two officers were assaulted and 17 protesters were arrested.  

Cleveland Police Chief Calvin Williams said a city police supervisor and an Ohio State Highway Patrol officer sustained minor bumps and bruises when they were punched and pushed during the commotion outside the Quicken Loans Arena.  

One protester accidentally lit himself on fire while igniting the flag. When an officer attempted to put out the fire, the protester resisted and the flames spread to two other people. They weren’t hurt.  

Two protesters were charged with felonies for assaulting two police officers and and 15 others were charged with misdemeanors for failure to disperse. Burning the American flag is legal.  

Until Wednesday, protests outside the convention hall where the Republican Party has crowned Donald Trump its 2016 presidential nominee have been peaceful.  

Williams said a small group was responsible for Wednesday’s fracas, which accounted for nearly all of the arrests so far.  

A massive media presence outside the hall gathered for the possibility of major disruptions during the political confab have complicated police efforts to respond to protests, Williams said.  

Witnesses described a chaotic scene on Wednesday night.  

Travis Cook, 20, was selling Donald Trump shirts when he said a small group of protesters arrived with bandanas covering their faces.

“Eventually we did see smoke,” Cook said.

Cook said police moved quickly and attempted to disperse the protesters, who locked arms. He said several were arrested.

Steve Jones, 32, said “no one could move” in the commotion that included a swirl of protesters, media and police.

“Police did a really good job,” Cook said. “They were completely there.”