Hundreds of protesters were arrested Wednesday night shortly after they marched onto Interstate 94 in Minneapolis, protesting among other things Donald Trump's presidency and his threat to challenge Tuesday's unsettled election results.

The march, which began at Cedar and Riverside avenues and looped through downtown, was organized by Twin Cities for Justice 4 Jamar in coordination with the National Alliance Against Racist and Political Regression. That group soon merged with a second protest endorsed by 30 organizations whose agendas ranged from pro-Black Lives Matter anti-police fervor to calling for action on climate change.

Organizers said the event had been planned even before Tuesday's presidential election, whose outcome remained uncertain late Wednesday as absentee ballots were still being counted in several states.

About 7:45 p.m., protesters marched onto Interstate 94 from Cedar Avenue, Minneapolis police said in a tweet. Officers quickly shut down both lanes of I-94 and asked motorists to avoid the area. Traffic was backed up and stalled in both directions.

Then Minneapolis police and State Patrol troopers, some on horseback, some in buses, surrounded and methodically arrested protesters on the freeway one by one on suspicion of trespassing and unlawful assembly.

The protesters were ordered to sit on the pavement and await arrest processing, which went on for more than two hours late Wednesday. As the night wore on, the mood even became festive; some protesters played music and danced as they awaited processing, and late Wednesday, officer announced via bullhorn that those who were cooperating would merely be cited and released.

Troopers and police made exceptions for several people, including parents with children, some of whom they allowed to walk away before being processed for arrest.

No injuries were reported.

"We have a racist in office. Which side are you on?" Nekima Levy Armstrong said to the crowd in the protest that preceded the walk onto the freeway. "Do you stand on the side of oppression or the side of justice? I'm tired of relatives of people killed by police coming to these rallies."

Other speakers said Democratic presidential hopeful Joe Biden cannot be trusted to champion causes dear to the protesters' hearts and that even if he wins the election, protests are likely to continue.

Staff writer Liz Sawyer and staff photographers Leila Navidi, Mark Vancleave and Renée Jones Schneider contributed to this report.

David Chanen • 612-673-4465