For the seventh night in a row, the officials have also used tear gas against protesters, even when a federal court order prohibits its use.
"Stay away from South West 3rd and South West Main Streets. We have detected that in that area agents are using tear gas, are throwing projectiles, and are hitting the crowd with club hammers and other weapons," Portland Police Department tweeted.
"Trump's undercover officers are increasing the possibility of a constitutional crisis," Portland Mayor Ted Wheeler stated as he recalled that Federal Agents were sent by the White House without authorization from local authorities.
On July 11, anger over the federal presence in Portland increased when a protester was hospitalized with serious injuries after an officer hit him in the head.
Last week, Oregon authorities reported that masked federal agents were harassing the crowd, arresting citizens without probable cause, and taking them into unidentified vehicles.
"Federal agents can't intervene in the city without any coordination with the state and the local authorities. This situation is unusual outside the context of a civil war," Cornell University professor Michael Dorf said.
On Monday, however, President Donald Trump promised to send federal security forces to other cities governed by Democrats, such as Chicago and New York.