Police officers from Norfolk and Suffolk are among hundreds from across the country sent to London to help deal with the Extinction Rebellion protests.
More than 1,100 climate change activists, including a number from Norfolk, have been arrested since Monday in action which has shut down part of the capital.
The Metropolitan Police made a request to the National Police Coordination Centre for extra support, which has seen four Norfolk officers and 12 from Suffolk police sent to London.
A spokeswoman for Norfolk police said: "Norfolk and Suffolk constabularies together have sent officers to London to support colleagues in policing the protests by Extinction Rebellion."
She said it was part of the nationally agreed mutual aid assistance arrangements.
Members of the Norwich Extinction Rebellion group have been among those arrested during the demonstrations.
Green Party city councillor Jamie Osborn, 25, was arrested after he superglued his hand to a road in London as part of the protests.
A specialist team and police took 30 minutes to dissolve the superglue and arrested Mr Osborn on Wednesday,
Other people arrested included Green Norwich city councillor Lesley Grahame, University of East Anglia professor and author Rebecca Stott, former Green group leader at City Hall and ex-county councillor Andrew Boswell and his wife Jacqui McCarney.
Former Green Norwich city councillor Rupert Read appeared as a spokesman for Extinction Rebellion on the BBC's Question Time programme on Thursday night.
The Extinction Rebellion protest, due to last for two weeks, is calling on the government to declare a climate emergency and to reduce climate emissions to net zero by 2025.
Demonstrations on Thursday focused on London City Airport.
Former Paralympic cyclist James Brown, climbed on top of a British Airways jet, prompting criticism from Metropolitan Police Commissioner Dame Cressida Dick, who described the act as "reckless, stupid and dangerous".
And Friday saw a blockade of the BBC's central London headquarters, with protesters holding banners urging the corporation to end its "silence" on climate change.
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