Police enforced a Section 14 notice to stop "serious disruption" to communities, after officers removed those camped out in Westminster.

Police have made 541 arrests over the two days of protests.

The prime minister has described the activists as "uncooperative crusties".

But campaigner and TV presenter Chris Packham said they are "the concerned people of the world."

Extinction Rebellion activists are protesting in cities around the world, including Berlin, Paris, Amsterdam and Sydney, and are calling for urgent action on global climate and wildlife emergencies.

Protesters say they are occupying 11 sites in central London and people have travelled from across the UK to take part in the demonstrations.

Activists glued themselves to a government department and to the underside of a lorry outside another.

A protester who attached himself to the top of a trailer with a bike lock for more than 28 hours in Trafalgar Square was arrested and removed from the area by five police officers.

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The Metropolitan Police said at 21:30 BST on Tuesday there had been 541 total arrests over the two days, including 261 on Tuesday.

Police have enforced a Section 14 Notice of the Public Order Act 1986, forcing those who wish to continue protesting to move to the pedestrianised area around Nelson's column in Trafalgar square.

Anyone suspected of breaching the condition - which has no time limit - could be arrested and prosecuted, police said.

A Section 14 order allows the police to impose conditions on a static protest - where campaigners are gathered in one place, rather than marching.

To impose the condition, police must have evidence that serious disruption is being caused to communities.

Activists have attached themselves to the underside of a lorry, which is blocking the road outside the Home Office.

The vehicle is parked on Marsham Street, where hundreds of protesters set up camp overnight. One activist climbed on top of the lorry and set up a tent.

There was a large police presence in the area on Tuesday, with pictures showing officers removing activists from the lorry.


Protesters have also glued themselves to the Department for Transport building - a tactic used in similar protests in April.

Two activists have attached themselves to the doors of the building, while others demonstrate outside.

Meanwhile, a group have placed 800 potted trees outside Parliament, in Old Palace Yard, as they call on the government to plant billions of trees across the UK.

Trees have been dedicated to MPs, and protesters hope they will use them to reforest the country.

Sean Clay, 36, from Newcastle, told the BBC: "Planting trees would go a long way to restore the habitats we have lost as well as absorbing carbon emissions."

Asked about Boris Johnson's description of demonstrators, Packham told the BBC's Victoria Derbyshire programme: "I was there yesterday. I met farmers, I met teachers, I met scientists, I met lawyers, I met grandparents, I met mothers and fathers, and I met children.

"These are the concerned people of the world."

Mr Johnson had suggested while attending a book launch on Monday that the demonstrators should abandon their "hemp-smelling bivouacs" and stop blocking roads.

Protester Claudia Fisher, 57, from Brighton said campaigners would like to discuss their views with the prime minister.

Responding to his description of activists as "uncooperative crusties", Ms Fisher said: "We are a little bit crusty, I'll put my hands up to it, after a night sleeping out on the grounds of Whitehall, but we're not uncooperative.

"We're actually very co-operative. We... would really like to hear what he has to say, and we'd really like him to... hear what we have to say."

John Curran, a 49-year-old former detective sergeant for the Metropolitan Police, was one of the protesters who camped overnight.

Mr Curran, who has a three-year-old daughter, says he was arrested while protesting with Extinction Rebellion in April, and is willing to be arrested again.

He said: "Clearly there is some frustration (for the police) that they probably have better things to be doing, and I agree, but the responsibility for that must lie with the government.

"Take action, and we won't have to be here."

Activists camped at Smithfield Market overnight, but say they allowed traders to operate.