Fifth-wave coronavirus infections in France are rising at an alarming rate, the government reported Sunday, with new daily Covid cases close to doubling over the past week.

The seven-day average of new cases reached 17,153 on Saturday, up from 9,458 a week earlier, according to the health authorities, an increase of 81 percent.

"The fifth wave is starting at lightning speed," government spokesman Gabrial Attal told media.

The latest seven-day increase is three times the average rise of cases recorded over the previous three weeks, indicating an exponential acceleration of infections.

For now the spike in infections has not led to a massive influx of Covid patients into hospitals, with the authorities attributing the limited number of intensive care patients to France's high rate of vaccinations which appear highly effective against the most dangerous forms of Covid.

On Saturday, hospitals reported a total of 7,974 Covid patients in their care, with 1,333 of them in intensive treatment.

This compares to 6,500 and 1,000, respectively, a month earlier.

"There is a very strong increase in infections, but we also know that in France we have a very large vaccination cover," he said. "We seem to be ahead of our neighbours concerning booster shots."

France's introduction of a health pass ahead of other countries in the summer was also helping to keep Covid in check, he said.

The health pass, required in French restaurants, cafes and many cultural venues, certifies that a person is fully vaccinated, has recently recovered from Covid, or has tested negative for the virus.

The government continues to stand by its choice to "bring the weight of restrictions to bear on non-vaccinated people rather than vaccinated people", Attal said.