Members of a specialized Portland, Oregon, police unit that deals with crowd control have resigned from the assignment en masse a day after a fellow officer was indicted on an assault charge stemming from alleged illegal use of force during a protest last year.

The Portland Police Bureau’s Rapid Response Team, which is primarily responsible for providing public safety at crowd events, consisted of approximately 50 officers, all of whom resigned Wednesday, the bureau announced. The assignment is voluntary and the officers will remain on the force and continue their regular assignments, the bureau said.

The mass resignation comes a day after a grand jury indicted Portland Police Bureau Officer Corey Budworth on one count of fourth-degree assault, a misdemeanor, for what prosecutors allege was an “excessive and unlawful use of force” during a protest in August 2020.

Budworth, who at the time was on the bureau’s Rapid Response Team, is accused of striking a woman in the head with a baton during an Aug. 18, 2020, demonstration outside the Multnomah Building. The indictment marks the first time a Portland police officer has faced prosecution for striking or firing at someone during a protest, according to the Oregonian.

The Portland Police Bureau placed Budworth on administrative leave Tuesday, officials said.

The officers, detectives and sergeants on the Rapid Response Team voted to offer their resignation from the assignment at a meeting Wednesday night, Acting Chief Chris Davis said during a press briefing.

Two law enforcement sources close to the team told ABC News the officers decided the assault charge reflected too much hostility towards their police work, and they did not see a way forward in being members of the team facing sometimes violent protests in downtown Portland.

Davis said the bureau, including the members of the Rapid Response Team, has been under a “tremendous amount of stress” due to the coronavirus pandemic and in the wake of the murder of George Floyd, during which he said Portland saw over 150 nights of “sustained civil unrest.”

“All that being said, as your police bureau, we are committed to providing the community the best service that we can,” Davis said. “This does not mean there will be no response in public order situations. We’ll use the resources that we have.”

In October, Daryl Turner, then-president of the Portland Police Association, the union representing officers, called on the city’s mayor and police chief to “stand up and publicly support Police Bureau members who voluntarily serve on the Rapid Response Team,” saying the officers were “exhausted and injured” due to the protests.

“The only glue holding their team together is their integrity and commitment to serve their city,” Turner wrote in an open letter. “They deserve better.”

Following the indictment, the Portland Police Association said in a statement that Budworth was “caught in the crossfire of agenda-driven city leaders and a politicized criminal justice system.”

The union said Budworth accidentally struck the woman, Teri Jacobs, in the head with his baton while trying to break up a riot, and alleged Jacobs was interfering with an arrest.

Jacobs filed a civil lawsuit against the city over her alleged physical and emotional injuries from the incident, which was settled earlier this year for $50,000, according to ABC Portland affiliate KATU.

In announcing the indictment over the incident this week, Multnomah County District Attorney Mike Schmidt alleged that “no legal justification existed for Officer Budworth’s deployment of force.”

“When that line is crossed, and a police officer’s use of force is excessive and lacks a justification under the law, the integrity of our criminal justice system requires that we as prosecutors act as a mechanism for accountability,” Schmidt said.

Schmidt released a statement in response to the mass resignation of the Rapid Response Team, saying, “I have confidence that the Bureau will continue their mission to maintain public safety. In the meantime, my office will continue to focus on the fair and just prosecution of criminal matters. We cannot expect the community to trust law enforcement if we hold ourselves to a lower standard.”

During near-nightly social justice protests in Portland last year sparked by the police killing of Floyd in Minneapolis, Portland police used force more than 6,000 times between May 29 and Nov. 15, according to a Department of Justice report.

This week, the Multnomah County District Attorney’s Office also confirmed it has referred an investigation of a Portland Police Bureau detective’s alleged use of force during protests for potential criminal prosecution to the Oregon Department of Justice.