Hundreds of thousands of people are marching worldwide to demand action to stop climate change, but one protest in Paris was marred by violence.
More than 2,000 events are happening globally on the eve of a UN summit in the French capital.
In Paris, police fired tear gas at a large group of demonstrators gathered in the Place de la Republique.
They were apparently protesting against France's state of emergency, and have been disowned by the main organisers.
Interior Minister Bernard Cazeneuve said 208 people were arrested, of whom 174 are still in custody.
The order, banning public gatherings, was put into place after the 13 November attacks in the city, in which 130 people died.
Many of those involved in the clashes wore masks or covered their faces. Protesters and police walked over candles and tributes left for the attack victims at a makeshift memorial.