UPDATE 2:10 P.M. TUESDAY: The Multnomah County District Attorney's Office has dropped its pursuit of misdemeanor criminal charges against the three anti-Trump protest leaders who were arrested Monday. Before a Tuesday court appearance, Greg McKelvey, Kathryn Stevens and Micah Rhodes were handed citations -- similar to a traffic ticket -- for allegedly failing to obey police.

Correction appended

Protesters blocked downtown Portland streets Monday as officers put several demonstration leaders in handcuffs in the latest rally and march to protest Donald Trump's election as president.

Gregory McKelvey, who helped start activist group Portland's Resistance in response to the election, and partner Kathryn Stevens were taken into custody near the same time police tweeted that protesters were blocking Southwest Fifth Avenue and "have ignored police direction."

Micah Rhodes, another prominent Portland activist, was later arrested near the Portland Police Bureau's downtown headquarters.

Police drove McKelvey and Stevens away in the back of an unmarked police car from where they were arrested near the Multnomah County Courthouse.

McKelvey, Rhodes and Stevens face a misdemeanor disorderly conduct allegation, according to police. Rhodes and Stevens also face a misdemeanor count of interfering with a peace officer.

Police said officers "observed McKelvey and Rhodes actively encouraging and directing student protesters to counter lawful police orders." They said they arrested Stevens "after she attempted to interfere with McKelvey's arrest."

Cameron Whitten, a Portland community advocate and frequent protest attendee, said outside the police precinct that he believed McKelvey's arrest was in retaliation because McKelvey declined an invitation from Mayor Charlie Hales to have his group participate in a city-sponsored rally set for Tuesday.

The mayor's office couldn't immediately be reached for comment.

The protest started as a crowd of about 100 -- primarily students from city schools -- gathered at Holladay Park in Northwest Portland and later marched across the Burnside Bridge to downtown on a route that seemed largely defined by police -- who addressed demonstrators from a speaker mounted on an SUV.

Officers on bicycles and motorcycles kept traffic away from the protesters -- except on the bridge, where the crowd defied police as some people marched through eastbound traffic and the group later sat on the bridge.

Protesters appeared to peaceful throughout, and no officers in riot gear were present.

So far 3 organizers were targeted by police and arrested. They were not violent and reportedly targeted for "fomenting civil disobedience". — PDX Resistance ✊ (@Pdx_resistance) November 22, 2016

The demonstration, dubbed a "Portland student solidarity protest," was organized by students in coordination with the Resistance. It began with an optional school walkout at 3 p.m.

Portland Public Schools sent out a note to the families of middle and high school students saying police had warned administrators that "some outside organizations" were encouraging students to participate in protests this week.

"The police are concerned about the safety of our students if they join any of these outside organizations in their demonstrations," the notice said. "We encourage open debate and dialogue, but in a non-violent manner."

Protesters of all ages have repeatedly taken to Portland streets in response to Trump's election as the nation's 45th president. Police have arrested more than 100 people after some of the demonstrations here turned violent.

Hundreds of students walked out of class and marched through Portland streets a week ago in a peaceful anti-Trump demonstration -- gathering at Pioneer Courthouse Square before heading to City Hall and through Southeast, Northeast and North Portland.

A Facebook event advertising Monday's protest said it's up to young people "to steer this country in the right direction."

Yanet Asghedom, a Grant High School senior and Hillary Clinton supporter, said it's important for young people to be involved in such demonstrations because they're the next round of voters.

Asghedom said she attended the demonstration to support immigrants such as herself; she came from Eritrea, which is in east Africa, almost four years ago.

Mia Palmer, another Grant senior and Clinton supporter, said she attended the demonstration to support black people, immigrants, students and the LGBT community. She said by attending protests, demonstrators expose themselves to different perspectives, giving them the chance to develop their own views.

Callie Quinn-Ward, one of the Facebook event hosts, said a group of Grant students are working to form an activist group called "Portland's Student Resistance."

It will look to convert anti-Trump energy into long-term local action, she said -- akin to Portland's Resistance, which she said inspired the students. She said the group, in part, aims to make Portland-area schools, communities and the city itself safe for everyone and champion progressive policy.

The group wants to get delegates from other metro schools to join, said Quinn-Ward, a 16-year-old Grant student.

The demonstration came a day before civic, community and faith leaders plan to hold a "March of Hope" beginning at the Salmon Street Springs fountain. Portland Mayor Charlie Hales is convening the demonstration -- during which Portland's Resistance plans to protest.

McKelvey and Stevens were released late Monday from the Multnomah County Detention Center, according to jail records. Rhodes was released early Tuesday.

-- Jim Ryan

jryan@oregonian.com

503-221-8005; @Jimryan015

A previous version of this report incorrectly stated the location of Holladay Park due to a reporter's error. The park is in Northeast Portland.