Dozens of university campuses in major cities across France are reporting COVID-19 outbreaks, according to various local media outlets.

The affected cities reportedly include Lyon, Marseille, Montpellier, Rennes and Toulouse.

In a recent interview with French newspaper Ouest-France, the country’s minister of higher education, Frederique Vidal, said the clusters of cases emerging on university campuses are “mostly linked to private gatherings,” such as student parties. Still, Vidal said she wants to maintain in-person classes “because it is important that teachers and students meet,” particularly first-year students “who need benchmarks.”

French student unions, on the other hand, have laid the blame on overcrowded lecture halls.

Since the start of the academic year, at least 81 schools across France have been closed and 2,100 classes have been cancelled due to COVID-19.

“We have seen around 1,200 new COVID cases among school pupils this week,” France’s minister of national education, Jean-Michel Blanquer, told reporters Wednesday. “Classes are closed as soon as there are three positive cases.”

ABC News’ Ibtissem Guenfoud contributed to this report.