Cressida Dick tells demonstrators to move to official site at Marble Arch as police try to clear Oxford Circus and Waterloo Bridge

The head of the Metropolitan police, Cressida Dick, has urged Extinction Rebellion activists to protest lawfully as officers continued a large-scale operation to clear environmental campaigners from sites at Oxford Circus and Waterloo Bridge in central London.

With more than 1,500 officers on duty at the protests, Dick has asked demonstrators to move to an officially designated site in Marble Arch or go home.

Facebook Twitter Pinterest Cressida Dick, the Metropolitan police commissioner, said on Sky News the protesters had caused ‘miserable disruption’. Photograph: Sky news

Later on Saturday, hundreds of police officers were clearing activists from a blockade on Waterloo Bridge, where protesters have been since the Extinction Rebellion disruption campaign started five days ago.

The Press Association reported that by 6pm officers had removed six campaigners who had been chained and glued to the underside of a lorry on the bridge in an operation that took almost six hours.

Patrick Greenfield (@pgreenfielduk) Quite the scene on Waterloo Bridge. Hundreds of police are here to clear the #extinctionrebellion protest camp. pic.twitter.com/7mCuOZnLs1

Earlier, crowds clapped and cheered as activists who had been chained to the road at Oxford Circus were lifted into police vans.

Police drafted in 200 extra officers to deal with the protests, which began on Monday and have resulted in more than 750 arrests. Officers said they would try to clear Oxford Circus by the end of the Saturday.

Speaking to Sky News, Cressida Dick said that “lots of people have had miserable disruption to their lives” because of the anti-climate change movement.

“I’ve got one message for the protesters: please, go to Marble Arch where you can protest lawfully, stop your unlawful protests, and if you don’t want to go to Marble Arch then go home.”

Play Video 0:17 Police drag climate change activists near Regent Street in London - video

An Extinction Rebellion spokesman at Waterloo Bridge said there were more than 100 officers on the bridge, with 14 police vans and a large tow truck at its south end and more vans at the north. “It looks like they are making a concerted effort to clear the bridge,” the spokesman said.

A video of police dragging demonstrators along the ground in an operation to remove a pink boat from Oxford Circus on Friday prompted concerns about police tactics against protesters, who have been polite and apologetic throughout.

Officers used angle grinders to cut through the bars below the hull of the Berta Cáceres boat, named after the murdered Honduran environmental activist, to which protesters had chained and glued themselves.

The intersection was calm on Saturday as bank holiday shoppers mingled with protesters, asking questions about the movement and its tactics.

Of the 750 people arrested in connection with the campaign as of 4pm on Saturday, which has included protests at Marble Arch and Parliament Square, 28 have been charged.

Q&A What is Extinction Rebellion? Show Hide Extinction Rebellion is a protest group that uses non-violent civil disobedience to campaign on environmental issues. Launched in October 2018, with an assembly at Parliament Square to announce a 'declaration of rebellion' against the UK Government, the group has staged regular demonstrations against current environmental policies. More than 1,000 activists were arrested in April 2019 after protesters occupied four sites across London, as well as blocking roads, disrupting a railway line and conducting a protest at Heathrow. Other demonstrations have included a semi-naked protest inside the House of Commons and blockading streets in London, Cardiff, Leeds, Bristol and Glasgow. The group says climate breakdown threatens all life on Earth, and so it is rebelling against politicians who “have failed us”, to provoke radical change that will stave off a climate emergency. The movement has become global with groups set up in countries include the US, Spain, Australia, South Africa and India. Martin Belam Photograph: Anadolu Agency/Anadolu

The Met said most of the arrests had been for breaching section 14 orders, which are in place in all the protest areas except Marble Arch. The force announced that on Friday it had renewed the order requiring protesters to clear Waterloo Bridge for a further three days.

On Saturday, police were accused of intimidating protesters, many of whom are young people, in an attempt to crush the movement. Mike Schwarz of Bindmans solicitors in London said he was concerned about elements of police conduct and tactics.

Schwarz, who is representing a large number of protesters, told the Observer that officers appeared to be attempting to scare people at the demonstrations, many of whom faced being arrested for the first time. By Saturday afternoon, only 28 people had been charged with an offence out of 750 arrested by 4pm.

Facebook Twitter Pinterest Demonstrators on top of a truck were surrounded by police as the blockade at Waterloo Bridge continues. Photograph: Wiktor Szymanowicz/REX/Shutterstock

“Police tactics, perhaps deliberately, run the risk of intimidating activists in the hope of subduing the protest,” Schwarz said. “Many of the arrests have been first-timers. The policing often appears disproportionate.”

He added: “There is concern about police conduct at the stations. They have been detaining people for hours – why are they keeping them in cells for so long? What is behind this? It might be a lack of resources, a lack of coordination and, simply, a war of attrition, where they are desperate to get people off the sites.”

Extinction Rebellion designated Oxford Circus a place to discuss the campaign with members of the public who have questions. On Saturday, bank holiday shoppers were keen to engage.

Michelle, 30, and Lee, 31, from St Helens in Merseyside, were eager to speak to activists during an Easter break in London after watching the campaign unfold on TV during the week.

“I agree with some of the points but I disagree with the methods,” Michelle said after a lengthy discussion with an activist, adding that the movement appeared quite London-centric.

“It wouldn’t happen in St Helens,” added her partner.

Milo, seven, was in Oxford Circus with his father and said he thought the protests were a good thing.

If climate change is not avoided, “it’s going to get so hot like Venus. Everyone is going to die and there’s going to be a total extinction. If the government listens, they might fly less planes and drive less cars,” he said.

Nick, a 56-year-old civil servant who was chained to the road at Oxford Circus, said it was “an unusual way to spend his annual leave”. He said he was not happy to be there and he did not take the possibility of being arrested lightly “but I’m going to be here as long as it takes”.

Facebook Twitter Pinterest Olympic gold medallist Etienne Stott joins Extinction Rebellion demonstrators on Waterloo Bridge in London. Photograph: Victoria Jones/PA

After actor Emma Thompson’s appearance at Oxford Circus on Friday, Olympic gold medalist Etienne Stott was among the latest celebrities to lend their support to the demonstrators. The London 2012 canoe slalom champion turned up at Waterloo Bridge after joining protests in Nottingham, and told the Press Association: “I joined the protests because I don’t think there is anything more meaningful that I could be doing in my life right now.

“The climate emergency is just such a serious thing, and for me I’m willing to put in as much time and energy as I can spare and try and use everything I can to try and make the situation better.”

The singer Charlotte Church tweeted her support saying that she would join the protesters in the future.

Charlotte Church (@charlottechurch) @ExtinctionR I'll be with you for the next one. I wanted to watch for a while, sorry not super brave,

but having seen how peaceful,creative, purposeful and family friendly your protest was I will join you next time. Thank you for your giving. Xx

Late on Saturday, just before midnight, there still appeared to be significant numbers of activists at three London sites – Waterloo Bridge, Oxford Circus and Parliament Square – despite the call from the Met chief to confine their demonstration to Marble Arch.