Extinction Rebellion activists intending to continue protesting in central London “must” go to Trafalgar Square or risk arrest, police have warned.

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.

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.