Thousands of protesters filled the streets outside Target Center as President Trump rallied the crowd inside. The demonstrations were generally peaceful, but there were some tense moments as the president’s supporters left the downtown Minneapolis arena.

Protesters started gathering along First Avenue hours before Trump and Vice President Mike Pence took to the stage.

Many blew whistles in support of the whistleblower who raised concerns about Trump’s July 25 phone call with Ukraine's President Volodymyr Zelenskiy.

Tom Hoch, who ran for mayor of Minneapolis two years ago, organized the whistle demonstration.

“Everywhere I went to buy more whistles they were already out. There are now people who’ve shown up with whistles and they’re passing them out and that’s a positive thing to do,” Hoch said. “I think it underscores the nature of what this man is doing and the fact that we as Democrats are going after him and holding him accountable.”

Debbie Weinstock, of Minneapolis, said this was her first political protest. The 60-year-old opposes Trump’s treatment of women and migrant children, and his decision to move U.S. troops from northern Syria.

“I have been against this administration from day one. But having him come to Minneapolis where I live in my community and spread hate and division. I just could not tolerate it anymore,” Weinstock said.

The downtown Minneapolis skyway system kept most Trump supporters around the block and a story above the street protests. People with Trump-Pence 2020 shirts and Make America Great Again hats queued for hours in the bridge leading to the arena.

Still, some of the president’s backers did mill around with demonstrators. And occasional rain showers pushed everyone together under the skyway.

Tony Bolduc was there wearing his Trump hat and carrying a rainbow-colored sign that said ‘love everyone, yes even Trump supporters.” It was a nod to talk show host Ellen DeGeneres, who received heavy criticism on social media after appearing at a football game with former President George W. Bush.

Bolduc said he got a lot of positive feedback from people who don’t share his political views.

“I left a lot of conversations with handshakes and even embraces. We’ve been struggling in this country ever since Trump got elected. And hopefully what Ellen did, that’ll start the healing,” he said.

Though Bolduc hoped to set a tone of polite political discourse, tensions on the street ratcheted up as Trump whipped up the crowd inside. He attacked former Vice President Joe Biden and his son Hunter, took swipes at Mayor Jacob Frey and U.S. Rep. Ilhan Omar, both Democrats, and said past administrations should have restricted immigration from Somalia.

Protesters stand outside of the Target Center where President Trump is holding a rally on Thursday, Oct. 10, 2019. Andy Kosier | MPR News

For much of the evening, protesters packed onto First Avenue between Sixth and Seventh streets shoulder to shoulder, chanting occasionally. The gathering was generally peaceful, but after the rally ended and Trump supporters left the arena some skirmishes broke out.

There was a heavy and visible police presence. At one point late in the evening, officers used their bicycles as a barrier to separate protesters from people driving out of a parking lot.

At least twice, protesters swiped Trump hats from people’s heads and ran. In one case a middle-aged man ran back to retrieve his cap. There was pushing and shoving but no one was hurt. At another point, protesters surrounded a younger man who was wearing Trump gear, but he was able to leave uninjured.

On several occasions police sprayed small amounts of chemical irritants. It was noticeable in the air, but MPR News reporters and photographers at the scene did not see anyone who’d been incapacitated by it.

At least one person was taken into custody, but Minneapolis police have yet to release details on the number of arrests.