A day ahead of planned protests in Paris against rising fuel prices and taxes on petrol, a French minister warned that lawmakers had been threatened by angry demonstrators.

"You have deputies who have been threatened by angry citizens," Parliamentary Affairs Minister Marc Fesneau told broadcaster Public Senat.

"People have a right to be angry but nobody has a right to give out the personal addresses of members of parliament, or even in some cases to call for the homes of members of parliament to be vandalized," he added.

France has seen days of protests and blockades by protesters wearing yellow high-visibility jackets. Hundreds of people have been injured or arrested. Two have died in traffic incidents linked to the protests.

Interior Minister Christophe Castaner said Friday evening that a police operation was taking place in the Angers area, where a person wearing a yellow jacket and carrying "an explosive grenade" had announced he was carrying explosives and demanded to meet President Emmanuel Macron.

Police special forces were evaluating the situation, Castaner said.

Local authorities later clarified that the man was at a car wash rather than, as Castaner had said, a petrol station, adding that his demands were not yet clear.

Castaner appealed to protest organizers to declare their plans to police in line with French law, saying that was necessary to protect everyone.

Security services last week dismantled a "terrorist network" that was planning an attack last Saturday, when 283,000 people took part in the first wave of "yellow jacket" protests, Castaner said.

Paris police chief Michel Delpeuch warned protesters not to try to assemble on the city's Place de la Concorde, as suggested in several calls on social media, or other areas near the Elysee Palace.

Authorities have said that protesters can rally at the gardens around the Eiffel Tower, a slightly less central location.

But the decision has not been welcomed in the largely leaderless movement. "We aren't going for a giant picnic on a patch of grass," one activist told broadcaster BFMTV.

The government says it will not give in to protesters' demands to cancel planned rises in petrol and diesel taxes.

It has promised to aid poorer motorists and those who need to regularly travel long distances, but those measures do not appear to have placated the protesters.