Police made one arrest as the Extinction Rebellion protests which closed down central London passed peacefully.
Activists marched through the capital on Saturday staging sit-down protests along the route as they called for an end to investment in fossil fuels.
A Met Police spokesman said: “A man was arrested for obstructing the highway on Oxford Circus at about 17:10hrs during today’s protests. He was taken into custody at a central London police station.”
Hundreds of demonstrators gathered at Speakers’ Corner at Hyde Park in the morning before moving to Oxford Street and Regent Street, where they sat in the road and blocked traffic in the heart of the capital’s shopping district.
They chanted “save our planet” and “whose streets, our streets” and waved multicoloured flags and banners that read “I am here for nature and children”, “navel gazing into disaster” and “life on earth is dying”.
The crowd later headed to Trafalgar Square, where they sat on the roundabout on the edge of Whitehall while a band of drummers played near the base of Nelson’s Column.
The Met tweeted that traffic diversions were in place at the square.
Olympic gold medal-winning canoeist Etienne Stott was among the demonstrators, saying he was participating because he was “really scared for the future” of the planet.
Extinction Rebellion has vowed to “block areas of the city for as long as possible” every day for at least a week, and on the next three weekends.
The environmental activist group plans to recruit new “rebels” and hold training in non-violent action and resistance tactics in Hyde Park in the mornings before marching into the city centre “en masse”, it said on its website.
“Our disruption will not stop until the fossil fuel economy comes to an end,” it said.
In a video posted to Twitter, Met commander Ade Adelekan said the force has a “comprehensive plan” to respond to the action next week and that “people can expect to see our officers out and about across London”.
Some activists dressed as Prime Minister Boris Johnson, Chancellor Rishi Sunak and Home Secretary Priti Patel, carrying placards lambasting the Government’s handling of the climate crisis.
A member of the public who wanted only to be named as Steve C, 50, of Ealing, west London, lashed out at Extinction Rebellion’s “obsessive” tactics.
He said: “The tactics have given the Conservative Party an excuse to reduce and remove all of our rights to protest.
“They have daily, repeatedly, blocked roads, whether it is small or large numbers. They have stopped people from taking their kids to school, they have stopped people from getting to work and to hospital appointments. It is just unacceptable.”
Protester Sunita Ramani, 23, of Bristol, who works in environmental communications, said the action was justified.
“It’s absolutely not our intention to annoy people and disrupt their lives but looking throughout history civil disobedience has proven to be the most successful way that people are able to make movements like this successful,” she told PA.
“We are doing this on behalf of everyone who deserves to have a liveable, justice-filled future.”
On Friday, two Extinction Rebellion protesters shut down Tower Bridge by abseiling off the sides of the landmark and unfurling a huge banner that read: “End fossil fuels now.”