This is a pattern. A couple of days ago, a Muslim mob attacked police in France, and the attack below is related to a May 20 incident in which a Muslim mob attacked the cops.
NB Google translate
"At a rally against Islamophobia linked to an attack on a veiled woman on May 20, young protesters have taken this afternoon, violently, to the Commissioner of Argenteuil, as well as a other responsible local police.
Earlier, the deputy mayor of Argenteuil, Philippe Doucet, had come to explain to a crowd of a thousand people. Heckled and booed, he had escorted back to the mayor.
By late afternoon, the lawn of the Town Hall was still occupied by protesters. "