Electricity supply in the country was down by 3.7 gigawatts as output dropped at two nuclear reactors and several thermal plants, the media outlet reported, citing data from power provider EDF. No disruption was reported at hydraulic power plants, but EDF posted a strike notice for Thursday.

Meanwhile, French refineries also reported trouble due to the walkouts, with TotalEnergies saying they were causing interruptions in the shipping of petrol products. However, the company rushed to assure consumers that no shortages have so far been recorded at fueling stations, and that supply levels were largely satisfactory.

A spokesman for the CGT union told Reuters there were delivery disruptions at the Donges, Normandy, Feyzin, Oudalle, and Flanders refineries, with roughly 75% of staff on strike.

The French government presented its pension reform plan earlier this month, which will raise the retirement age for most French workers from the current 62, the lowest in the EU, to 64, and increase the total number of years people must work in order to qualify for a full pension.

Polls show that the majority of the population, over 60%, oppose the reform, and French workers’ unions claim the changes will punish people who started working at a young age or have been working in physically demanding jobs.