Clashes in Paris as tens of thousands mark May Day

Paris riot police fired teargas as they squared off against hardline demonstrators among tens of thousands of May Day protesters, who flooded parts of the city Wednesday in a test for France's zero-tolerance policy on street violence.

Tensions were palpable as a mix of labour unionists, "yellow vest" demonstrators and anti-capitalists gathered in the French capital, putting security forces on high alert. More than 7,400 police were out on the streets with orders from President Emmanuel Macron to take an "extremely firm stance" if faced with violence.

The clashes kicked off as crowds gathered on Montparnasse Boulevard, with hundreds of black-clad anarchists weaving their way to the front as thousands of unionists and yellow vests were quietly munching their lunch in the sun.

Suddenly they pounced, hurling bottles and chunks of broken paving stones at the security forces, shouting: "Everyone hates the police!" Clouds of teargas wafted into the air as the police hit back immediately, charging at the rioters and throwing stingball grenades to break up the crowd in clashes that lasted over an hour.

But the initial violence and the sporadic clashes that followed fell short of the "apocalypse" threatened by hardliners, with the security forces heading off some of the excesses seen in recent months.

Authorities had warned this year's marches would likely spell trouble, coming barely a week after leaders of the yellow vest anti-government movement angrily dismissed Macron's offer of tax cuts.

Some 40,000 people turned out for the May Day rallies in Paris, an independent media count estimated, while unions gave a figure of 80,000 and the interior ministry put the number at 28,000.

Ministry figures for the whole country gave a turnout of 164,000 people, while France's powerful CGT union gave a figure of 310,000 at events in some 250 towns and cities.

The sudden violence caught many marchers by surprise, with union members who were caught in the crossfire infuriated by what they claimed was an indiscriminate police crackdown.

"I've never seen anything like it, not even in '68," said one union member with tears in his eyes, referring to the momentous student-led protests in Paris that took place that year. "It was outrageous."