Police detain 100 protesters after Paris climate protest turns violent
* Thousands march in global climate rally
* Shoes laid out in central Paris to mark absent marchers
* World leaders meet for climate summit from Monday
About 100 people have been detained after a protest seeking a global climate deal turned violent, Paris's police chief said.
Michel Cadot told reporters that police identified about 200 or 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 Paris.
Mr Cadot said today about 100 people who were found to have projectiles or other suspicious objects were detained.
Police fired numerous rounds of tear gas on protesters to disperse them.
The protesters were gathering ahead of critical global warming talks outside Paris.
Those taking part in the unofficial protest formed a human chain as they gathered to urge world leaders to take action on global warming ahead of the global environment summit.
However a small group, most wearing masks, turned violent and lashed out against police.
They repeatedly chanted: "State of emergency, police state, you will not deprive us of our right to demonstrate."
Public demonstrations have been temporarily forbidden in France following the terror attacks on November 13 meaning that climate change activists were forced to abandon plans for a large demonstration in Paris.
Several police helicopters could be seen hovering above the gathering.
A very tense stand-off followed the violence, as police officers moved to block all avenues leading to the famous square.
Some members of the crowd chanted "liberty" "state of emergency" and "police state".
The violence comes as tens of thousands of people joined one of the biggest global days of climate change activism today, from Sydney to Berlin, to put pressure on world leaders to unite in fighting global warming at a summit in Paris.
About 20,000 pairs of shoes were laid out in the Place de la Republique in the French capital, from high-heels to boots, to symbolise absent marchers after attacks by Islamic State militants killed 130 people on Nov. 13 and led France to ban a protest that was meant to be at the heart of the global action.
Organisers said the Vatican sent a pair of shoes on behalf of Pope Francis. One activist, dressed in white as an angel with large wings, held a sign saying "coal kills".
More than 2,000 events were being held in cities including Sydney, Berlin, London, Sao Paulo and New York, making it perhaps the biggest day of climate action in history on the eve of the Paris conference which runs from Nov. 30-Dec. 11.
In Sydney, about 45,000 people are estimated to have 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 harbour city.
Protesters held placards reading: "There is no Planet B," and "Say no to burning national forests for electricity".
U.S. President Barack Obama and China's Xi Jinping will be among more than 140 leaders attending the start of the summit.
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 Paris attacks and banned the march in Paris on security grounds.
But activists plan to form a human chain, with about 3,400 people joining arms along what had been the original 3-km (2-mile) route through central Paris from the Place de la Republique to Place de la Nation.
"This is a moment for the whole world to join hands," said Iain Keith, campaign director for Avaaz, one of the organisers.
Alix Mazounie of French Climate Action Network said the activists reckoned a human chain would not violate the state of emergency. "This is not civil disobedience," she said. The chain would break, for instance, wherever it crossed a road to avoid disrupting traffic.
But, underscoring security worries, 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.
Many environmental activists want a phase-out of fossil fuels and a shift to 100 percent renewable energies by 2050.
Some marches were held on Friday and Saturday, from Melbourne to Edinburgh. "Don't be a fossil fool," one Australian banner said.
In the biggest single march on climate change ever staged, last year organisers estimated 310,000 people took part in New York.
On Saturday, faith groups delivered a series of petitions signed by 1.8 million people urging stronger action, collected on pilgrimages to Paris. "The time for talking is long over," said Yeb Sano of the Philippines, who walked 1,500 km from Rome.