HUNDREDS of thousands of people took part in marches and demonstrations around the planet yesterday to demand that world leaders gathering for a summit in Paris take urgent action on climate change.

More than 2,000 events took place on the eve of the UN summit intended to achieve a legally binding and universal agreement on climate, from all the nations of the world.

In Paris, police fired tear gas at hundreds of protesters near the Place de la République. They had gathered despite a ban imposed by the French authorities after the attacks of November 13.

About 100 people were detained after they were found to have projectiles or other suspicious objects, according to Michel Cadot, Paris’s police chief.

Cadot told reporters that police identified about 200 to 300 people who violated a ban on all protests under the country’s state of emergency.

The state of emergency was declared because of recent extremist attacks that killed 130 people in the French capital.

Using the state of emergency rules, police put 24 green activists under house arrest ahead of the summit, saying they were suspected of planning violent protests.

There were suggestions that at least some of the group were protesting against France’s state of emergency, as well as climate change.

Police fired numerous rounds of tear gas on protesters to disperse them. Images showed demonstrators and police walking over candles and tributes left at a makeshift memorial to victims of the attacks.

On Twitter, Prime Minister Manuel Valls said that the clashes showed a lack of respect to the memorial.

Nicolas Haeringer, France campaigner for environmental group 350.org, said: “We will stand against any attempts by the French authorities to use the incidents this afternoon to unnecessarily clamp down on civil liberties and prevent the types of demonstrations that are at the heart of any democracy and climate progress.”

Earlier, around 10,000 took part in a 2-mile human chain where people linked arms along the route of the banned march.

Activists left a gap in front of the Bataclan concert hall, where 89 people were killed.

More than 20,000 pairs of shoes had been laid out in the Place de la République to symbolise those frustrated in their plans to take part.

Included among the sports shoes, flip flops and high heels were a pair of black shoes sent by Pope Francis, who has been a vocal advocate for action to prevent dangerous climate change, and trainers from UN Secretary-General Ban Ki-moon.

One activist, dressed in white as an angel with large wings, held a sign saying ‘coal kills’.

“This is a moment for the whole world to join hands,” said Iain Keith, campaign director for Avaaz, one of the organisers.

More than 600 artworks critiquing world leaders and corporate sponsors of the summit such as AirFrance and Volkswagen have been installed in advertising spaces across Paris by the Brandalism campaign.

Elsewhere, more than 2,000 events were held in cities including London, Sao Paulo and New York, making it very likely the biggest day of climate action in history.

Activists marched, some dressed as polar bears or penguins and chanted slogans such as ‘climate justice’.

In Sydney, about 45,000 people marched through the central business district towards the Opera House, some with placards reading: ‘There is no Planet B’ and ‘Say no to burning national forests for electricity’.

Almost all the demonstrations were peaceful but, after the human chain protest in Paris, riot police fired tear gas and clashed with about 200 protesters, some wearing masks, in the Place de la République.

Around 50,000 people took part in a march in central London, where Labour leader Jeremy Corbyn addressed crowds.

He was joined by fashion designer Vivienne Westwood and actress Emma Thompson. “This is our planet and we are in deep, grave danger,” Thompson told reporters.

The Paris summit will be attended by about 150 heads of government. US President Barack Obama and China’s Xi Jinping will be among the leaders attending the start of the summit, which organisers hope will produce a first legally binding agreement to commit both rich and developing nations to curbing emissions of greenhouse gases, blamed for warming the planet, beyond 2020.

Many say pledges made in Paris will be insufficient to limit a rise in global temperatures to 2 degrees celsius above pre-industrial levels, widely viewed as the threshold for dangerous changes in the planet’s climate.