PARIS (AP) — Environmental activists in Britain and France stepped up campaigns Saturday to get their governments to confront climate change with greater urgency, part of a week of global climate actions.

Thousands of people marched in south Paris to press French President Emmanuel Macron, world leaders at the United Nations and multinational companies to reduce greenhouse emissions faster.

The protest turned violent for a while after dozens of marchers dressed in black broke windows and set fire to makeshift street barricades. Police blocked off side streets and used tear gas and batons indiscriminately to disperse the crowds as demonstrators ran for cover.

Around the busy Port of Dover, the English port nearest to France and a main transport link, activists from the Extinction Rebellion group launched a “blockade” to “highlight the vulnerability of the UK’s food supply in the face of the ecological and climate emergency”. Ten people were arrested.

Saturday’s protests come a day after hundreds of thousands of mostly young people marched, rallied and demonstrated around the world, demanding action to combat climate change. The Global Climate Strike took place Friday in advance of a United Nations climate summit.

France’s Macron will be among those speaking at the UN summit Monday. While he has presented himself as a champion of environment issues and stood up to Brazilian President Jair Bolsonaro over the burning Amazon rainforest, climate activists aren’t convinced of Macron’s sincerity.

On Saturday in Paris, a delegation from Greenpeace pulled a giant float caricaturing Macron as a “King of Blah Blah”.

Clement Senechal, a Greenpeace climate campaigner, accused Macron of putting business interests ahead of protecting the environment.

“The statue embodies the approach of Emmanuel Macron regarding the climate issue, which is mainly a smoke screen of fake, false measures,” Senechal said. “We are facing climate inaction in France, and we have a big gap between claims and deeds.”

Demonstrators raised concerns ranging from ongoing fossil fuel subsidies to deforestation and meat consumption. Dozens of France’s anti-government yellow vest protesters joined climate activists to emphasise the link between economic grievances and environmental concerns.

“We are here, we are here. Even if Macron doesn’t want it, we are here,” marchers chanted.

The protest march remained largely peaceful, but troublemakers wearing black who mingled among the marchers broke shop windows, drew graffiti on buildings and set fire to trash cans and scooters.

Taking shelter from tear gas inside an apartment building along the protest route, Danielle Joly called the police response “a total disgrace”.

“I’m 69. I’m not going to fight with the police. I’m with other friends of a similar age, and our group has been gassed for no reason whatsoever,” Joly said. “And the way we interpret it is that it’s an intimidation, so people don’t demonstrate anymore.”

Around Dover in southeast England, the Extinction Rebellion protest disrupted some traffic, but police said the majority of the group’s activists stayed within the designated protest area.

The protest was given the go-ahead by local authorities within certain limits, and Extinction Rebellion insisted it would “not cause any disruption to vital supplies” such as medicines.

As well as being a major cross-channel ferry crossing between England and France, Dover plays a crucial role in the free-flow of trade between Britain and the European Union.

It handles around 12 million passengers a year and around 120 billion pounds ($150 billion) of UK-EU trade. Its importance to the British economy is a crucial point of discussions in the Brexit negotiations.

Police said that there was a brief closure of the A2 highway, one of the main roads into Dover from London, after some people obstructed traffic. They said 10 people were arrested on suspicion of public order offences and would remain in custody pending investigations.

“It is pleasing we haven’t seen levels of disruption greater than what could be reasonably expected,” said Chief Superintendent Andy Pritchard.

Protesters also hung giant banners showing the Extinction Rebellion “XR” emblem from Dover Castle and the town’s iconic white cliffs.