(Reuters) - A group of people caught up in unrest in Ferguson, Missouri, after a white officer killed a black teenager, sued local officials on Thursday, alleging civil rights violations through arrests and police assaults with rubber bullets and tear gas.

Police officers keep watch while demonstrators (not pictured) protest the death of black teenager Michael Brown in Ferguson, Missouri August 12, 2014. REUTERS/Mario Anzuoni

The suit, filed in U.S. District Court for the Eastern District of Missouri, says law enforcement met a broad public outcry over the Aug. 9 killing of 18-year-old Michael Brown with “militaristic displays of force and weaponry,” (and) engaged U.S. citizens “as if they were war combatants.”

The lawsuit seeks a total of $40 million on behalf of six plaintiffs, including a 17-year-old boy who was with his mother in a fast-food restaurant when they were arrested. Each of the plaintiffs was caught up in interactions with police over a period from Aug. 11 to 13, the suit allege.

Named as defendants are the city of Ferguson, St. Louis County, Ferguson Police Chief Tom Jackson, St. Louis County Police Chief Jon Delmar, Ferguson police officer Justin Cosmo, and other unnamed police officers from Ferguson and St. Louis County.

Neither the city, county nor police departments had any immediate comment on the lawsuit.

The lawsuit followed nearly two weeks of racial strife in the St. Louis suburb of Ferguson, where Brown’s killing prompted protesters to take to the streets. Some stores were looted in nightly protests, and police responded with riot gear and moved in military equipment to try to quell the turmoil.

One of the plaintiffs alleges she and her son were in a McDonald’s restaurant when several police officers with rifles ordered them out. According to the suit, an officer threw her to the ground and handcuffed her, with she and her son both arrested.

Another plaintiff alleges he was trying to visit his mother in Ferguson when several police officers in military uniforms in her neighborhood shot him with rubber bullets. When he fell over, he was beaten and sprayed with pepper spray, the lawsuit says.

Two other plaintiffs say they were peacefully protesting when officers in riot gear fired on them with tear gas, rubber bullets and stun grenades. A separate plaintiff says he was trying to record footage of the protests when police took his camera and arrested him.

“This is a blatant example of how police handle African-Americans ... how it can go terribly, terribly wrong. You have a right to peaceful assembly,” said attorney Reginald Greene who brought the case.

Police have said police officer Darren Wilson shot Brown in an altercation on a residential street when the officer asked him to move out of the road. Some witnesses have reported that Brown was holding his hands up in surrender when he was shot multiple times, including twice in the head.

A St. Louis County grand jury has begun hearing evidence in the case. The U.S. Justice Department has opened its own investigation.