3 cities where agitators attacked police during 'No Kings' protests on Trump's birthday

At least four federal officers injured in Portland

At least four federal officers were injured during a clash with rioters on Saturday outside the U.S. Immigration and Customs Enforcement office in Portland's South Waterfront.

Several demonstrators also used a stop sign as a battering ram at some point in the evening to shatter the ICE facility doors, according to a report on Sunday from Oregon Live. The U.S. Department of Homeland Security states that violent rioters "stormed an ICE facility after launching fireworks, hurling smoke grenades, and throwing rocks at federal law enforcement."

The officers used smoke and tear gas to disperse the crowd. Demonstrators formed a "shield wall" near the ICE facility's main gates around 5 p.m., and around 6:30 p.m., the authorities declared the demonstration a riot and ordered the crowd to disperse. 

Later in the evening, the Portland Police's Rapid Response Team issued another announcement on social media, warning that it had "observed criminal activity including assault and criminal mischief and will be making targeted arrests." 

"Do not interfere with Police action," the alert stated. "Failure to adhere to this order may subject you to citation or arrest." 

The violent clash followed a "No Kings" protest that occurred in the city earlier in the day, with similar demonstrations taking place throughout the country in protest of President Donald Trump's administration.

On its website, No Kings outlines its commitment to nonviolent action and discourages event attendees from bringing weapons of any kind. 

In a Sunday press release, the PPB announced that three individuals had been arrested in relation to the protest outside the ICE facility on Saturday. The offenses ranged from attempted assault of a public safety officer, first-degree criminal mischief, harassment, interfering with a peace officer and first-degree theft. 

Portland Mayor Keith Wilson addressed the Trump administration in a Sunday statement, denying that the city required assistance from the federal government. The mayor added that Trump sending the military to help quell protests in the city should be seen as "unwarranted, unprecedented, and unconstitutional."

"If we witness federal abuse following this incident or any other pretext, we will bring it to light, take legal action, and take the fight to federal courts, where we will prevail," Wilson wrote.