Protesters hold letters that spell Count Every Vote as they cross an overpass while marching in Portland, Ore., Wednesday, Nov. 4, 2020, following Tuesday's election. Credit: Marcio Jose Sanchez / AP

Police arrested dozens of people in New York, Portland, Oregon, and other cities overnight at protests demanding all votes be counted in the race for the White House, while smaller groups backing President Donald Trump returned to tabulation sites in closely contested states to cry foul over the election.

In Minneapolis, police cited more than 600 demonstrators who marched onto a highway Wednesday night protesting Trump’s threats to challenge the election results, as well as a variety of social injustices, authorities said Thursday.

The protests came as the Trump campaign insisted, without evidence, that there were major problems with the voting and the counting of ballots.

In Portland, some marchers smashed the windows of businesses and hurled fireworks at officers as uncertainty over the election combined with months of unrest over racial injustice and other causes. Police made at least 12 arrests.

As the city cleaned up on Thursday, Oregon Gov. Kate Brown drew a line between a peaceful gathering by marchers aligned with the Black Lives Matter movement and “self-styled anarchist protesters” who damaged buildings, including a church that feeds the homeless.

“Indiscriminate destruction solves nothing. These are acts of privilege,” she said.

In New York, where hundreds of people paraded past boarded-up luxury stores on Manhattan’s Fifth Avenue, police arrested 25 and issued summonses to 32 others.

Demonstrators in Chicago marched through downtown and along a street across the river from Trump Tower. Protesters also gathered in cities including Los Angeles, Houston, Pittsburgh and San Diego.

The protests came as smaller groups of Trump supporters gathered at vote tabulation sites in Phoenix, Detroit and Philadelphia, decrying counts that showed Democrat Joe Biden leading or gaining ground.

In Phoenix, at least two dozen Trump supporters gathered outside City Hall on Thursday morning, chanting “Protect our vote!” The group said it planned to return to the tabulation center, where demonstrators Wednesday night lashed out at Fox News for declaring Biden the winner in Arizona.

Observers from both major political parties were inside the election center as ballots were processed and counted, and the procedure was live-streamed online at all times.

In Detroit, a few dozen Trump supporters gathered outside the city’s convention center Thursday morning as election workers counted absentee ballots inside. The protesters held signs that read, “Stop the steal” and “Stop the cheat.”

A small group of counterprotesters gathered on the other side of the street, and the two sides shouted at each other. Trump supporters occasionally mocked those on the other side over a loudspeaker.

Michigan Attorney General Dana Nessel, a Democrat, insisted Wednesday that both parties and the public had been given access to the tallying, “using a robust system of checks and balances to ensure that all ballots are counted fairly and accurately.”

Story by Martha Bellisle and Adam Geller, The Associated Press. AP reporters Gillian Flaccus in Portland, Terry Tang in Phoenix and Claire Galofaro in Detroit contributed to this report.