Seattle police are working to clear out a protest zone in the city that has become "lawless and brutal" after weeks of violence, including four shootings and the deaths of two teenagers, the city's police chief says.
Officers, wearing extra protective gear, entered the city's "autonomous zone" early on Wednesday and have so far arrested 13 people, according to the police department's Twitter feed.
They observed vehicles circling the area carrying passengers with firearms and armour, although there were no reports of violence, it said.
The move to retake the zone came after Seattle Mayor Jenny Durkan declared the gathering of people in and around the police department's East Precinct and Cal Anderson Park an "unlawful assembly," the police chief, Carmen Best, said in a statement.
The precinct was abandoned weeks ago after protesters clashed with police outside the station house after the May 25 killing of George Floyd, a black man, at the hands of Minneapolis police.
Floyd's death triggered a wave of demonstrations against racial injustice and police brutality across the US, giving rise to the zone east of downtown Seattle termed the Capitol Hill Autonomous Zone (CHAZ) or Capitol Hill Occupied Protest (CHOP).
"The CHOP has become lawless and brutal. Four shootings - two fatal - robberies, assaults, violence and countless property crimes have occurred in this several-block area," Best said in a statement.
US President Donald Trump has been demanding that Washington state and Seattle take action to eject the protesters, calling them "domestic terrorists," but city authorities had until Wednesday taken a non-confrontational approach.
Seattle's bicycle police employed about three dozen of their bikes to create a barricade at East Pike and 12th Avenue, shutting off the previously occupied zone to allow Department of Transportation crews to take down protesters' tents.
Dozens of police cruisers lined surrounding streets, as uniformed officers stood guard, some sipping Starbucks' coffee.
Small groups of people, at least one carrying a tent, milled about nearby but it was not immediately clear whether they were bystanders or protesters.
"Officers continue to give dispersal orders and are checking Cal Anderson restrooms," the police department said.
"Thank you to the individuals affiliated with the CHOP who have assisted officers in encouraging people to safely leave the area."
As evidence of the recent violence, Seattle police posted an open-source video showing men brandishing handguns and audio clips in which gunfire was heard.
One clip showed an apparent gunshot victim slumped in a car seat, with the window blown out.
The zone has diminished in size and scope over the past several days.
Crowds that came by the thousands to listen to speeches about police brutality and marvel at street art commemorating black lives have disappeared, as have medic stations and multiple free food tents.