Walkouts jolted all of France on Tuesday with serious disruptions in public transport as well as oil refineries, local media reported.
This is the sixth round of demonstrations against the government's proposed pension reform.
Labor unions have called for a nationwide strike while the Senate is still debating the reform plan.
At the national railway company SNCF, 80% of the high-speed trains TGV Inoui and Ouigo were canceled, as well as almost all of the intercity lines, according to daily Le Parisien.
Severe disruptions were also seen in the SNCF Paris region train lines.
Parisian regional transport operator RATP's only fully operational lines are 1 and 14, which are automated.
The other RATP metro lines are having serious disruptions too, and most of the buses are not operating in the northern Lille city, while not a single tramway is functioning in the southern Nice city.
Transportation between France and the UK is also disrupted, with dozens of trains and flights being canceled.
Railway company Eurostar announced that 16 out of 26 planned trains linking Paris to London, and six others linking Brussels to London were canceled, daily Le Figaro reported.
The railway operator warned that disruptions may continue in the following days.
British airline EasyJet canceled 18 flights and British Airways canceled 13 flights between the UK and France, while Air France canceled four flights from London to Paris.
Some students also took action in the morning, as Racine High School students in Paris blocked the school building.
Oil refineries blocked
TotalEnergies Tuesday morning said 64% of their refinery workers were on strike, according to daily Le Figaro.
General Labor Confederation, a French trade union, announced that oil refineries were blocked on Tuesday and fuel transfer to stations was halted, the daily also reported.
TotalEnergies assured consumers that they will not suffer from fuel shortages at the gas stations where stocks are quite high, it added.
Hundreds of demonstrations will be organized across the country to protest the reform plan.
Workers and unions' representatives already gathered in Paris, and protests began in other cities including Nice.
French intelligence is expecting between 1.1 million and 1.4 million protesters in 320 demonstrations on Tuesday, according to broadcaster BFMTV.
Paris alone will see 90,000 protesters, it added.
The pension reform plan, which have triggered public outrage as soon as it was revealed last year, includes raising the retirement age from 62 to 64 by 2030 and requiring at least 43 years of work to be eligible for full pension.
