Hundreds of thousands of people took part in rallies around the world on Sunday, calling on leaders to take steps at an upcoming conference in Paris toward halting climate change.

The long-planned U.N. climate conference comes amid a state of emergency in France imposed after the Nov. 13 Paris attacks that bans marches, so many of the rallies are taking place outside the country.

But violence erupted between French riot police and a group of several hundred at a major square that was the site of a peaceful demonstration earlier. Police fired tear gas to disperse protesters throwing projectiles, and the city's police chief said about 100 people were detained.

A well-known climate pressure group, 350.org, distanced itself from the violent demonstration in Paris, saying the protesters were "unaffiliated with the climate movement."

The clash in Paris was an early test of the authorities' determination to ban public protests under the country's state of emergency declared following the Nov. 13 attacks by Islamic State in Iraq and the Levant (ISIL) fighters that killed 130 people.

Protests held around the globe were timed to put pressure on more than 140 world leaders, including President Obama and China’s Xi Jinping, who are gathering for the high-stakes talks that will run from Nov. 30 to Dec. 11.

On the eve of the talks, the 53-nation Commonwealth announced that it wants the climate conference to produce a legally binding agreement to reduce greenhouse gas emissions.

The Commonwealth — a grouping of Britain and many of its former colonies — covers more than 2 billion people and includes industrialized economies such as Canada and Australia, resource-hungry India and small island states vulnerable to rising sea levels.

"Many of our most vulnerable states and communities are already facing the adverse impacts of climate change ... (and) for some it represents an existential threat," Commonwealth leaders said in a statement at a summit in Malta that ended Saturday.

The United States has cast doubt on whether an agreement reached in Paris would be legally binding. Secretary of State John Kerry said this month that there were "not going to be legally binding reduction targets" agreed on at the meeting.

In other developments, The Associated Press is reporting that countries, high-powered companies and business leaders will announce an effort Monday to put tens of billions of dollars toward clean energy technology to fight climate change.

A French source who was not authorized to speak publicly told The Associated Press that French president François Hollande will attend the event they call the "Clean Tech Initiative" that is going to be launched by Microsoft founder and philanthropist Bill Gates in the presence of President Obama.

The source said France, the U.S., India, South Korea, Saudi Arabia, Australia, Canada and Norway have already decided to participate in the "ambitious" project that will aim at developing clean energy.

Climate activists held more than 2,000 events Sunday in cities that included Sydney, Berlin, London, São Paulo and New York, organizers said.

In Sydney, an estimated 45,000 people marched through the central business district towards the Opera House. Among them Sydney's Lord Mayor Clover Moore, who tweeted it was the largest climate march ever held in the harbor city.

Protesters held placards reading: “There is no Planet B,” and “Say no to burning national forests for electricity.

In Hong Kong, two protesters carried styrofoam polar bears holding signs reading "homeless and hungry" and "please help" because of melting Arctic ice. In Seoul, hundreds of protesters banged drums and danced.

Activists in France scaled back their plans when the government imposed a state of emergency after the attacks and banned the march on security grounds.

They laid out about 20,000 pairs of shoes, from high-heels to boots, in the Place de la République to symbolize absent marchers. Organizers said the Vatican sent a pair of shoes on behalf of Pope Francis.

They also planned a human chain of thousands of people, which they reckoned would not violate the state of emergency. "This is not civil disobedience," said Alix Mazounie of French Climate Action Network prior to the demonstration. The chain would break, for instance, wherever it crossed a road to avoid disrupting traffic.

France put 24 green activists under house arrest before the summit, Interior Minister Bernard Cazeneuve said on Saturday, saying they were suspected of planning violent protests at the talks.

Faith groups on Saturday delivered a series of petitions signed by 1.8 million people urging stronger action. "The time for talking is long over," said Yeb Sano of the Philippines, who walked over 900 miles from Rome.

Pub: Al Jazeera America, http://america.aljazeera.com/articles/2015/11/29/paris-activists-clash-w...