More than 2,500 new coronavirus cases were registered in France in 24 hours in the sharpest increase since May, government data showed on Wednesday, as officials said indicators were "clearly worsening".

Of 600,000 tests over the past week, more than 11,600 were positive, the health ministry's DGS public health division said. At 2.2 percent, the weekly rate of positives was up from 1.6 percent the week before, confirming "increased viral circulation", it added.

"Indicators used for tracking the epidemic on French territory have clearly worsened in recent days," the DGS said. With August traditionally a month when many French people take weeks of summer holiday, "it's imperative that we keep up our efforts to avoid the epidemic picking up again, individually and collectively, everywhere and at all times", the DGS said.

Health officials identified 18 new virus clusters in the past 24 hours, bringing the total to 896 nationwide. But the number of patients in intensive care dropped slightly to 379, a level relatively steady since late July.

Almost 30,400 people have died of coronavirus in France since the epidemic began, the third-heaviest toll in Europe after Britain and Italy.