French health authorities are currently investigating 68 COVID-19 clusters and urging people to continue to respect social distancing rules.
Five new clusters were identified on Tuesday, according to the National Health Agency, Santé Publique France, bringing the total number under investigation to 68.
Authorities define a cluster as "the occurrence of at least three confirmed or probable cases, in a period of seven days, and which belong to the same community or have participated in the same gathering of people, whether they know each other or not."
The northern half of the country and overseas territories continue to be more severely impacted.
In the north-western department of Mayenne, six clusters have been identified in recent weeks with the number of confirmed cases quadrupling from 54 to 219 between June 25 and July 6. To cope with this abnormal increase, a mass screening plan has been launched and all residents over the age of 10 have been urged to get tested. This affects approximately 300,000 people.
Four of the clusters have been observed in the department's administrative centre, Laval, with a slaughterhouse, a nursing home, a school and an accommodation and assimilation centre impacted. The two others are located in another slaughterhouse and a home for young workers in Craon, around 35 km south of Laval.
In Montargis, a city of 65,000 inhabitants in the north-central department of Loiret, more than 2,000 people were tested between Saturday and Monday. Only two among the first 1,000 tests came back positive, bringing the total number of confirmed cases in this cluster to 50.
Authorities have not communicated on the origin of the cluster but the mayor of Montargis, Benoit Digeon, raised the possibility of a family celebration.
In the country's second city, Lyon, 450 pupils and staff of a local school were told to self-isolate on Monday after six cases were recorded. All have been urged to get a test and to quarantine for 14 days even if it comes back negative.
In the south-western Nouvelle-Aquitaine region, two new clusters were identified earlier this month. The city of Bordeaux also flagged a probable cluster after an infected person said he had been in contact with 23 people recently.
Overall, 304 clusters were recorded across the country between May 9 and July 1. Mainland France accounted for 284 of them, with the remaining 20 recorded in overseas territories.
According to Santé public France, the average number of cases detected by cluster is 15.6. In total, the clusters identified were the cause of 4,742 cases.
The country is amongst the worst impacted by the deadly virus with 29,965 fatalities and 169,473 infections recorded since the beginning of the outbreak.
The daily tally of infections and fatalities has dwindled since late May, prompting the government last month to speed up its plan to ease lockdown restrictions. On Tuesday, health authorities reported 663 new cases and 34 deaths in hospitals.
But Jérôme Salomon, France's top health official continues to call on people to be cautious, stressing that the country "must prepare for a resumption of the epidemic, even a second wave".
He added that it is necessary to "anticipate an epidemic rebound this autumn or this winter" because the "virus (...) is still circulating."