Lyon, Grenoble, Lille and Saint-Etienne have joined Marseille and Paris at the highest level of Covid-19 alert, with 20,339 new cases recorded nationally – a new record for daily infections.
Hospitals in northern France have been warned to prepare for a huge influx of coronavirus sufferers needing intensive care, and are advised to postpone all non-Covid related treatment.
The availability of emergency beds in the city of Lille, with its 1.2 million inhabitants, is described as "close to critical".
Lille's University Hospital is one of the largest public health centres in northern Europe.
The 800 bars and cafés in the city will be obliged to close for two weeks from Saturday. The same regulations and closures come into effect in Lyon, Grenoble and Saint-Etienne.
In further extending the maximum alert zone on Friday, French health minister Olivier Véran accepted that the decision would cause hardship and be costly for certain professions. But he insisted that the restrictions were absolutely necessary.
The average infection rate for the whole of northern France has been higher than the national average for the past two weeks, and is now estimated at 157 cases for every 100,000 inhabitants. The corresponding national figure is 116 cases.
Lille leading a worrying trend
In the city of Lille itself, the infection rate is currently running at 308 cases per 100,000, a situation described as "worrying" by the Regional Health Agency (ARS).
More than 30 percent of regional beds in intensive care are now occupied by coronavirus sufferers.
Of particular concern for the ARS is the fact that the spread of the virus is particularly marked among those in the over-60 age group, persons know to have an advanced risk of developing a severe form of Covid-19.
Huge impact of absent staff
Another worrying development in Lille's University Hospital, with a staff of 16,000, is the number of those failing to show up for work.
Although, of the 9,000 staff so far tested, the infection rate has been just 5.2 percent...described as "satisfactory" by the hospital managers...the rate of staff absenteeism is around 12 percent, with as many as 1,500 of those rostered to work failing to report.
"It's an indication of the general level of exhaustion among staff," according to the director general. "We're taking on new employees as fast as we can, and we hope to maintain the new staff levels once this crisis is over."