Ryanair was among airlines that announced widespread disruptions, saying in a statement it canceled more than 400 flights affecting 70,000 passengers. The company said the strike affects all its flights over French airspace, as well as traffic in and out of French airports, and urged the European Union to reform air traffic rules.

A walkout by French air traffic controllers to protest against staff shortages and ageing equipment forced airlines to cancel hundreds of flights on Thursday, just as the summer season gets under way.