PARIS - Depicting the object of their ire as Napoleon, Dracula, Jupiter, a banker-king and Margaret Thatcher, tens of thousands marched through central Paris on Saturday to protest against President Emmanuel Macron's sweeping reforms, a year after he took office.

Some 2,000 security officials, including riot police, were deployed just in case a generally good-natured rally went the same way as May Day protests hijacked by anarchists.

Marchers gathered from midday in warm early summer sunshine in the central Opera square for a protest dubbed a "Party for Macron", a tongue-in-cheek "celebration" of the 40-year-old centrist and former Rothschild banker's first anniversary in power.

Paris police put the number of marchers at 40,000 but organizers said it was 160,000.

"It was not the huge influx that they had predicted," Interior Minister Gerard Collomb said, denouncing what he called an "attack" on an outside broadcast van of Franceinfo radio in the eastern quarter of Bastille, where the march ended.

One of its windows was smashed and a smoke bomb thrown inside the vehicle.

"Luckily no journalist was inside when the smoke bomb was thrown," Collomb said.

Smaller rallies took place in the southern cities of Toulouse and Bordeaux while the Paris one kicked off with a mass picnic which drew numerous families.