PARIS (AP) — Thousands of people around France protested a proposed bill that could make it more difficult for witnesses to film police officers, with tensions quickly rising at the Paris march Saturday as intruders set fire to several cars, broke windows and tossed objects at police.

The protest-crashers, who disrupted a similar demonstration a week ago, formed a barricade on a section of the march route in eastern Paris. Dressed in black and known as "black blocs," the aggressive interlopers are a feared element at French demonstrations.

Police officers who have come under fire for alleged racism and gratuitous violence within their ranks, were hard-pressed to stop the individuals seeding chaos at the march attended by several thousand people.

President Emmanuel Macron triggered anger among police unions during a Friday interview with young French people in which he said that officers with violent behavior and “racist attitudes” must be tracked and sanctioned. Macron announced plans for a online platform the public can use to report and discuss misconduct and acts of bias by police officers.

In reaction, major police unions pressed colleagues to stop carrying out identity checks, which activists see as prime opportunities for discrimination.

Saturday’s marches drew a diverse lot of protesters, but was focused on a security bill that includes an article aimed at outlawing the publication of images of police officers with intent to cause them harm. The provision caused such an uproar that the government decided earlier this week to rewrite it. Critics fear it could impinge on press freedom and make it more difficult to expose police brutality.

Police misconduct has received fresh attention in France after video footage emerged last month of officers beating up a Black man.