April 19 (UPI) -- London's Metropolitan Police started clearing Oxford Circus of protesting environmental activists Friday an escalated show of force after days of demonstrations.
Officers wore jackets saying "protester removal team" as they entered a ring of other police around a pink boat protesters had used as a rallying point all week.
Some had criticized police officers spotted dancing and skateboarding with "Extinction Rebellion" demonstrators in the streets.
Oscar-winning actress Emma Thompson appeared at Oxford Circus on Friday to support the protesters.
"We have seriously failed them and our planet is in serious trouble. We have much, much less time than we thought," Thompson said. "I have seen the evidence for myself and I really care about my children and grandchildren enough to want to be here today to stand with the next generation."
Police had made hundreds of arrests at four locations in central London as protesters continued to disrupt traffic and cause delays for commuters. Marble Arch, Waterloo Bridge and Parliament Square have also been sites of persistent environmental protests.
While police have publicly complained about the strain the protests have put on its resources, the peaceful nature has limited their ability to use more strident tactics.
"We have been asked why we are not using tactics such as containment -- physically and forcibly stopping the protesters from moving around," Metro Police said in a statement Thursday. "The simple answer is we have no legal basis to do so. These are peaceful protesters; while disruptive, their actions are not violent toward police, themselves or other members of the public."
Authorities said they started stepping up efforts Thursday to corral the protests, arresting more than 450 people for obstructing roadways since Monday. But that has led to some protesters being released as jails fill up, only to see them immediately rejoin the demonstrations.