On June 30, Oregon Gov. Kate Brown signed into law a bill that bans tear gas except in situations that police declare to be a riot and announce out loud that tear gas is imminent before deploying it.

Hours later, as protesters gathered in Northeast Portland and marched toward Portland Police Association headquarters, the Portland Police Bureau declared a riot—and deployed tear gas onto protesters. Officers also arrested three journalists.

The use of tear gas against protesters falls in the wake of a federal lawsuit against the city of Portland, and a temporary restraining order issued by Chief U.S. District Judge Marco Hernandez that banned through July 24 the use of tear gas and "less than lethal" munitions in Portland except when there is an immediate threat to public safety.

"Tear gas shall not be used to disperse crowds where there is no or little risk of injury," Hernandez wrote.

Now, in a June 30 filing, the plaintiffs of the lawsuit, Don't Shoot PDX, are asking Hernandez to find the city of Portland in contempt of court for violating the restraining order.

"The ink was barely dry on the order before the City violated it," the filing says. "There does not appear to be any effort to avoid exposing entire crowds of people to pepper spray; indeed, officers appear at times to be acting in open defiance of that prohibition."

Last night, June 30, hundreds of protesters gathered near the police union's headquarters on North Lombard Street.

Police arrested three journalists, including freelancer Cory Elia. Police charged Elia with two counts of assaulting a police officer—a felony—and misdemeanors that included resisting arrest, disorderly conduct and interfering with a peace officer.

Police also arrested KBOO reporter Lesley McLam and charged her with one count of rioting, a felony, and one count of interfering with a peace officer. Police also arrested a filmmaker who anonymously operates the Twitter account @PDocumentarians.

Police say demonstrators began forming barricades with dumpsters after 9 pm, and that some demonstrators threw projectiles, including "large baseball-sized rocks" at the officers.

After 10 pm, police declared a riot, granting themselves permission under the new tear gas law to deploy gas on the crowd. They continued to deploy tear gas and other crowd control munitions.

After midnight, fewer than 100 of the remaining demonstrators marched toward the bureau's North Precinct, where days earlier they had attempted to barricade the building. By 1:15 am, most protesters had dispersed and gone home.

PPB says it arrested several protesters last night, but their names have not yet been released.

Videos from last night's protests show officers at times chasing protesters en masse in what is known as "bull rushing." As they do, videos show, police announce over the sound truck repeatedly that their actions are lawful.

In its lawsuit, Don't Shoot PDX calls the Police Bureau's actions a violation of both the court's orders and the U.S. Constitution.

"This theme is directly in opposition to the overall purpose of both of this Court's orders: that people engaged in passive resistance should not be subjected to these high levels of force," Don't Shoot PDX says in its June 30 filing. "This Court must act to remedy the contempt."

Judge Hernandez has not yet responded to the plaintiffs' filing.

On Wednesday afternoon, Portland Police Chief Chuck Lovell tweeted out a video statement regarding the Tuesday night protests. He said multiple officers were injured.

"This is bigger than property. It is about human lives," Lovell said. "CS gas is uncomfortable, but effective at dispersing crowds. We would rather not use it. We would rather have those in the area follow the law and not engage in dangerous behavior.…When tools are restricted that help us disperse crowds, the options are limited to batons or physical force."

Police actions received widespread condemnation today, including from Oregon House Speaker Tina Kotek, who said on Twitter that she would seek to expand the tear gas law if the ban wasn't effective.

At least one observer sided with the police: Black civil rights leader Ron Herndon. "The cops have been called every name but a child of God," Herndon said. "The police have shown more restraint than I could ever muster up."