Anarchists crash May Day rally in Paris, burning cars and smashing shop windows

Activists smash windows of a McDonald's restaurant after it was hit with petrol bombs during the traditional May Day rally in the centre of Paris, France. Photo / AP

Hundreds of masked anarchists and Black Bloc affiliates were arrested in Paris today, Reuters reported, after rioters burned cars and smashed shop windows during the city's May Day rally.

What was once an event with roots as a spring festival in European pagan cultures has evolved into an international day of marches in the name of worker rights. But these May Day celebrations have been regularly marred by violence since at least the 19th century.

Activists smash windows of a McDonald's restaurant after it was hit with petrol bombs during the traditional May Day rally in the centre of Paris, France. Photo / AP

Paris got the worst of it this year. Somewhere between 20,000 and 55,000 marchers gathered in the capital, according to Reuters, intending to march peacefully against President Emmanuel Macron's plans to roll back labour protections.

But about 12000 "masked and hooded protesters" dressed in black stood on the sidelines, according to the news agency.

Some were anarchists, some waved Soviet flags, and some were antifascists - upset by a gathering of far-right European leaders in France on the same day.

The gathering tipped into violence.

The protesters' coloured smoke bombs mixed in the air with tear gas, water from police cannons and petrol bombs. Before the chaos subsided, vehicles had been set on fire, windows at a McDonald's smashed out, several shops looted and 200 people detained, Reuters reported.

Four people, including a police officer, reportedly suffered minor wounds.

"When you come with molotov cocktails, it's to burn cops," a police union official said, according to Reuters. He added that the protesters had been allowed to target buildings, lest they be provoked into attacking people.

"Those who wear hoods are the enemies of democracy," government spokesman Benjamin Griveaux said after the violence, according to Reuters.