PARIS, Nov 3 — Students blockaded dozens of high schools across France today to maintain pressure on the government over education reforms as trade unions prepared for a nationwide strike later this week.

After returning from a two-week autumn break yesterday, some students resumed their protest campaign, calling on authorities to renovate dilapidated schools, reduce class sizes and create more university places.

Authorities said 48 out of France’s 3,700 high schools were blocked, including in cities such as Paris, Rennes, Toulouse and Lyon. The Union syndicale lyceenne (USL) contested those figures, saying 500 establishments were blocked.

The student union denounced what it called heavy-handed tactics, with “young people pinned against walls and riot police units deployed” outside schools.