PARIS

The workers’ strike at nuclear power plants in France extended on Thursday as employees from Western Europe's most powerful nuclear power plant also joined the action.

Workers at the Gravelines power plant (Hauts-de-France region), operated by French power producer EDF, have also joined the strike movement, which could cause delays in work ahead of the resumption of some reactors, according to local media reports.

The Gravelines employees are demanding a 5% increase in gross pay, threatening to delay the grid connection of one of the six 900-megawatt reactors, which will be shut down this weekend for annual maintenance and will be restarted before the end of the year.

"The strikes may affect certain maintenance operations," EDF said in a statement.

Strikes have been going on for several weeks at other power plants in France in order to get wage rises and inflation allowances.

The strikes are, in some cases, delaying tests that are needed to be carried out before nuclear power plants can be restarted after planned maintenance or work to resolve corrosion problems.

With the energy crisis looming and winter on the horizon, a delay in the restart of nuclear power facilities might exacerbate tensions in France.