One of France’s largest and most hardline trade unions, the CGT, organized a mass demonstration in Paris on Tuesday. The protest was in reaction to a new labor reform law, which the government claims will make France’s economy more dynamic. Union leaders, however, describe the law as a sell-out to management that would encroach on the workplace rights of employees.

Tuesday’s events saw thousands of demonstrators storm the streets of the capital. Protesters hurled stones at police officers, smashed windows, and lobbed Molotov cocktails. Police officers, in turn, arrested over a dozen of activists, after firing volleys of teargas and using a water cannon to break up groups of rioters.

The protest comes at an exceedingly tense moment for France. The country has been under a state of emergency since the November 2015 terror attacks. Compounding the tension, hundreds of thousands of soccer fans have come to the country for the Euro 2016 Championships.

Watch “Quick Hit: Paris Labor Protests Turn Violent”