The number of patients with coronavirus in French intensive care units rose on Saturday to a new high for this year, increasing the pressure to impose new restrictions that President Emmanuel Macron says will probably be needed.
France had 4,791 ICU patients being treated for Covid-19, up from 4,766 on Friday, health ministry data showed.
The numbers are approaching a peak recorded in mid-November during the second wave of the virus, although last spring, when France imposed its first lockdown, saw a peak of more than 7,000.
Doctors say intensive care units in the worst-hit regions could become overwhelmed.
The government's commitment to keeping schools open has been called into question due to rising case numbers among students and opposition from teachers, who are threatening to walk out.
Spain said on Saturday it would require people arriving by land from France to show a negative coronavirus test result.
Macron this week defended his decision not to impose a third full lockdown, but said further restrictions would probably be needed.
Three additional regions, including the Rhone department around Lyon, on Saturday joined other regions including Paris in closing non-essential stores and restricting travel. Police were out in Paris, Nice and other cities enforcing the rules.
The government is also trying to speed up a stuttering vaccination campaign.
France expects to receive 3 million doses of vaccines this week, rising to 4 million a week in a month's time, junior industry minister Agnes Pannier-Runacher told Europe 1 radio.
As of Saturday, more than 7.7 million people had received a first dose of vaccine, the health ministry said.
France's Covid-19 death toll, at almost 95,000, is the eighth-highest in the world.