Police officers have been criticised by their own commander after being caught on camera dancing with Extinction Rebellion climate protesters and skateboarding in the street.

Met Police officers were spotted larking around with activists at Oxford Circus and skateboarding at the Waterloo Bridge blockade, where a ramp has been set up.

The videos emerged as the number of arrests so far during the environmental protests rose to 428 on Thursday.

Metropolitan Police Commander Jane Connors said she was “disappointed” by a video appearing to show officers dancing with protesters.

She said: “I’m disappointed by the video and the unacceptable behaviour of the officers in it.

“We expect our officers to engage with protesters but clearly their actions fall short of the tone of the policing operation at a time when people are frustrated at the actions of the protesters.

“We will be reminding officers of their responsibilities and expectations in policing this operation – however the majority of officers have been working long hours and I am grateful to them for their continued commitment.”

Scotland Yard said enquiries are being made to identify the police officers involved.

Huge crowds remained at Oxford Circus for the fourth day (EPA)

Police have begun charging climate change activists who were involved in direct action, including three protesters who allegedly glued themselves to a train on Wednesday.

Cathy Eastburn, 51, Mark Ovland, 35, and Luke Watson, 29, appeared in court on Thursday.

Eastburn, of Lambeth, Ovland, of Keinton Mandeville, Somerset, and Watson, from Manuden in Essex, appeared at Highbury Corner Magistrates’ Court.

They ere all pleaded not guilty to obstructing trains or carriages on the railway by an unlawful act contrary to Section 36 of the Malicious Damage Act 1861.

But they were denied bail by district judge Julia Newton. She remanded them in custody and they will next appear at Blackfriars Crown Court on May 16.

The march’s organisers say they are prepared to escalate the group’s tactics if their demands “are not met” – with “thousands more rebels” expected to join in the coming days.

Dr Gail Bradbrook, a co-founder of the Extinction Rebellion group, said demonstrators would continue to act.

Speaking from Waterloo Bridge, Dr Bradbrook told the Press Association: “The charges might put some people off and we escalated our strategy by focusing on the rail infrastructure.

She said the disruption is “how things change”, adding: “There’s a key piece of a rebellion where you have to escalate your tactics.”

Swathes of police moved in to make more arrests, with 428 now arrested (Extinction Rebellion)

The group has had “very heated discussions about what’s for the best” in terms of its methods, she said.

“It’s certainly an option that tactics will be escalated if our demands are not met,” she said.

Asked about whether key sites like Waterloo Bridge will remain held for two weeks as planned, she said: “It’s in the hands of the gods really isn’t it? It’s up to whether people respond to the call to come onto the streets.

“More people are joining us all the time. We’re having a fantastic time here. It’s how life is meant to be lived with people coming together and actually exerting their political power.”

Part of Oxford Street continued to be closed off on Thursday, with the presence of a large pink boat – from which a DJ has been playing music to throngs of supporters – obstructing the main junction with Regent Street.

A mile west, a community of around 100 tents remain at Marble Arch, while swarms of climate protesters swelled on Waterloo Bridge.

The police presence at the bridge was thin during rush hour on Thursday morning, but noticeably increased as groups of officers slowly started to descend on the protest hub.

A handful of protesters also blocked traffic on one carriageway of Vauxhall Bridge Road, a short distance from Parliament Square, forcing some motorcyclists and cyclists to cross onto the opposite carriageway towards oncoming traffic.