Protesters wearing yellow vests demonstrate on the Promenade des Anglais in Nice, southern France, on Saturday.
Speaking about the death, French Interior Minister Christophe Castaner said: "That's the reason why we were worried to have people (who are) not experienced organizing protests."
Ecology Minister François de Rugy called on citizens to "respect caution and safety recommendations" in order for protests to go ahead "without a new tragedy," in a tweet Saturday. He also offered his condolences to the family of the victim.
More than 1 million people were expected to turn out for demonstrations across the country on Saturday. Partway through the day, the numbers were much lower than that.
Interior Ministry officials told a news a conference that about 125,000 people in total had taken part in some 2,000 rallies across the country.
"Honestly we're satisfied, even if it's true we are not hundreds of thousands people here, but still, people have come. The day is not over yet and we're glad that there are no incidents here," Thierry Paul Valette, who helped organize a protest on the Champs Elysées in Paris, told CNN.
"We can't stand Macron's taxes any more, it's too much. We couldn't make ourselves heard through political parties or trade unions, so we had to do something."
