French police arrested at least 1,800 people across France after violent groups clashed with officers and looted shops during nationwide protest marches, authorities said. The unrest erupted on Saturday as masked groups set fires and attacked public buildings, including city halls, in several cities. In Limoges, flames engulfed the 19th-century City Hall and its roof collapsed, the prefect said, adding the fire was deliberately set. French President Emmanuel Macron is set to hold an emergency meeting with government officials before addressing the nation later Sunday. Authorities said the protests drew hundreds of thousands, with 550,000 taking part according to authorities and organisers counting about 800,000. Interior Minister Laurent Nunez said more than 500 police officers, gendarmes and firefighters were injured. Paris prosecutors said a person died of a heart attack, without details. Paris police reported 855 arrests in the capital region, with 557 kept in police custody. In the aftermath around Place de la République, dislodged cobblestones, shattered storefronts and broken glass marked the damage. Police said dislodged crowds also included unauthorised marches in central Paris, and that a later phase brought large groups whose aim was to steal and loot. The government and local leaders condemned the violence while political rivals used the fallout ahead of next spring’s presidential election. Police and prosecutors have not linked the riots to immigrants, attributing some violence to radical far-left groups and other people who joined to loot. Legal status: arrests have been made, and some suspects are in police custody as investigations continue, including a probe into the heart-attack death reported in Paris.