Thousands of environmental protesters blocked access to landmarks and roads in central London, in an attempt to force the British government to declare climate change an emergency.
Activists converged on Marble Arch, Oxford Circus, Piccadilly Circus and Parliament Square on Monday, while some smashed windows and daubed graffiti at the offices of energy giant Shell, near Waterloo.
At sites across the British capital, campaigners chanted slogans and held placards that read “There is no Planet B” and “Extinction is forever”.
Activists say the roadblocks could last for two weeks.
By Tuesday morning, 113 adults had been arrested, most for breaching public order laws and obstructing a highway, London’s Metropolitan Police said.
The figure includes three men and two women who were arrested at the UK offices of energy giant Royal Dutch Shell on suspicion of criminal damage.
The protests are being led by the Extinction Rebellion group and will involve demonstrations in 80 cities in 33 countries around the world in the coming days.
The group, which made headlines earlier this month when some of its members held a semi-nude protest in the British parliament during a Brexit debate, has warned its members they could face arrest for participation in non-violent civil disobedience.
“The aim is to contribute to an escalating series of acts of civil disobedience which bring about change,” said Larch Maxey, 46, a spokesman for the movement.
“The plan is disruption and that disruption escalates until you get the attention of the people you are persuading to change,” he said.
Extinction Rebellion, which was launched in October by academics, wants the government to declare a climate and ecological emergency, reduce greenhouse gas emissions to net zero by 2025, halt biodiversity loss and create “citizen assemblies on climate and ecological justice” to oversee climate policy.
Reporting from Marble Arch in central London, Al Jazeera’s Bernard Smith said the protesters planned to camp there for at least three days.
“They are using this new type of civil disobedience to get the message of climate change across,” he said. “They have even set up solar panels because their intention is to camp out here.
“They say they are doing it because of the frustration over decades of warnings over climate change being ignored – and the only way they can get people to take notice is to do this sort of civil disobedience.”
On Waterloo Bridge, demonstrators set up a skateboard ramp and vegetarian food stalls, while others marched up and down the bridge behind a group of drummers.
Ruby Brookman, 22, a volunteer who helps refugees, told AFP news agency: “I’m here because our generation is going to be affected by this.
“I work with refugees and we saw people moving with climate change: drought in East Africa a while ago, the recent hurricanes in Zimbabwe.”
Protester Olivia Evershed, 23, said climate policies must be altered quickly to prevent catastrophic changes.
“If we don’t do anything to change this, our children will die,” she told the Associated Press news agency.
Hollywood actor Willem Dafoe said he was sending a video message in support of the activists, telling them: “I’m with you.”