A strike at EDF (EDF.PA) began to cut into France's nuclear output on Saturday, according to data published by the leading utility.

The rolling walkout, which started on Friday, has led to a roughly 2.1 gigawatt (GW) drop - the equivalent of two reactors - in electricity output capacity of nuclear plants, according to the data.

The strike affected production at four nuclear reactors at the Tricastin power plant, as well as that of the second reactor at Flamanville, according to EDF data.

President Emmanuel Macron has vowed to go ahead with reforms that aim to raise the country’s minimum retirement age from 62 to 64, despite nationwide protests and strikes.

The EDF workers' walkout started well ahead of planned strike action on March 7 when unions have said France will be brought to a standstill in protest at the reforms.