Updated 11/25/15 – 4:49 p.m.

CHICAGO (CBS) — Prosecutors have dropped charges against an activist who has helped organize several protests against police violence, less than a day after he was arrested for allegedly punching a police officer during a march downtown in the wake of the release of the video showing the shooting death of Laquan McDonald.

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Malcolm London, 22, had been charged with felony aggravated battery of a peace officer, and fellow protesters immediately took to social media to call for his release.

When London appeared for a bond hearing Wednesday afternoon, Cook County prosecutors said the charge had been dropped, and London was immediately released from custody.

Before charges against London were dropped, at least one aldermen even joined the call to demand London be released, claiming police concocted the charges against him.

Almost 200 of his supporters had come to the courthouse to cheer him and demand his release.

“Last night being in this place, I’m glad to be with my people,” London said.

London — a poet and activist who has helped organize protests of police violence in Baltimore, New York, and Ferguson, Missouri — is a member of Black Youth Project 100, which helped organize Tuesday night’s protest march.

Ald Roderick Sawyer (6th), chair of the City Council Black Caucus, said London was arrested on “trumped-up charges.”

“My daughter was standing right next to him when they ambushed him, as she indicated. She called it a kidnapping,” Sawyer said.

The alderman said his daughter is a close friend of London’s and told him an unidentified white male in the crowd threw a smoke bomb, but someone pointed the finger at London, and police arrested him.

“They ambushed him and took him off into an unmarked car,” he said.

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London was one of five people arrested during a protest march after the city released video of the video of Officer Jason Van Dyke fatally shooting McDonald in October 2014.

Hundreds of protesters took to the streets of Chicago after the video was made public, and while the protests were mostly peaceful, there were a few scuffles between demonstrators and police.

Dozens of activists with Black Youth Project 100 gathered inside an art gallery in the South Loop on Tuesday evening to discuss the video, before marching downtown, chanting “16 times.”

After the group marched downtown, they shut down Congress Parkway east of the Jane Byrne Interchange for a short time just before midnight.

In some cases, protesters antagonized police officers with taunting chants and profane slogans. A few scuffles broke out, and police said five protesters were arrested, mostly for resisting police. Another man was arrested for allegedly striking an officer, while another was arrested for drug possession, and carrying a taser and a knife.

London, of the 4900 block of West Huron Street, was arrested around 7:30 p.m. Police alleged he punched an officer in the face during a scuffle in the 100 block of East Balbo Drive, where officers had blocked protesters from trying to cross the bridge toward Columbus Drive. Prosecutors did not elaborate on why that charge later was dropped.

Another protester, 38-year-old Dean Vanriper, of California, was arrested for felony possession of a controlled substance, misdemeanor unlawful use of a weapon, and misdemeanor possession of a deadly weapon. Police did not say what type or amount of drugs Vanriper was carrying, but said he had a taser and a knife. Vanriper has been ordered held without bail, according to Cook County Sheriff’s records.

(Credit: Chicago Police)

(Credit: Chicago Police)

Three other protesters were arrested for misdemeanor charges of resisting a police officer. Police said 25-year-old Johnae Strong, 26-year-old May Page, and 24-year-old Troy Alim were released without needing to post bail after they were arrested.

“The Chicago Police Department supports citizens’ 1st Amendment rights and goes to great lengths to ensure those rights can be exercised. While on the whole last night’s demonstrations were peaceful, a few isolated incidents resulted in five arrests related to resisting arrest and assaulting police officers,” police said in a statement Wednesday morning.

In the days leading up to the video’s release, city officials and community leaders had urged protesters to keep demonstrations peaceful, fearing the graphic images of McDonald being gunned down could spark riots similar to those in Ferguson, after the fatal shooting of Michael Brown by officer Darren Wilson; or those in Baltimore, after the death of Freddie Gray while in police custody.

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Police said four officers suffered minor injuries during the protests, including the officer London allegedly punched. One officer suffered a sprained ankle when he was pushed off his bike, another officer suffered a cut finger from a bottle thrown during the march, and another officer suffered an abrasion to the leg. Police said all four officers were treated at local hospitals.