One week after a third of French schoolchildren returned to classrooms there has been a worrying flare-up of about 70 COVID-19 cases linked to schools, the government says.
Some lower grades in schools were opened last week and a further 150,000 junior high students went back to the classroom on Monday as coronavirus restrictions were loosened by the government.
But French Education minister Jean-Michel Blanquer sounded the alarm on Monday, telling French radio RTL the return has put some children in new danger of infection.
He said the affected schools are being closed immediately. French media reported that seven schools in northern France were closed.
Blanquer did not specify if the 70 cases of COVID-19 were among students or teachers.
Given that the incubation period for the virus is several days, people are "likely" to have been infected before the reopening of the schools, he said.
France reopened about 40,000 preschools and primary schools last week, with classes capped at 15 students.
About 30 per cent of children went back to school, Blanquer said. The government has allowed parents to keep children at home.
French authorities have reported at least 142,411 people infected with the coronavirus and 28,108 deaths.
Australian Associated Press