A woman named Annette Williams is suing the city on behalf of all other peaceful protesters like herself ... who she claims got sprayed by cops with a chemical irritant "in retaliation" for opposing police tactics in the arrest and killing of George Floyd.

Williams says she and her daughter were peacefully protesting on a public sidewalk on May 28 when the Minneapolis PD drove past and sprayed the crowd, which she claims was presenting no danger to police.

She says the irritant was not being used to clear a path for vehicles either, because it was directed at protesters on or around a sidewalk. Williams says it forced her and others to remove face masks worn for COVID-19, and they began coughing uncontrollably.

She says she's "suffered from labored breathing and chest pain interfering with her daily activities" ever since. She adds that the incident had a "chilling effect" and discouraged protesters from exercising their constitutional right to free speech and peaceful assembly.

On top of all this, Williams claims the arrest of a CNN news crew the following day -- which as we reported, and went down live on the air -- underscores "the city and police force’s open infringement on first amendment rights."

According to the suit ... police have also engaged in a "corral and combat" strategy against protesters in an effort to concentrate them in one location, then gas them and shoot non-lethal projectiles at them. Williams claims this has "no tactical purpose other than injuring otherwise peaceful protestors."