German citizens have been urged to stick to coronavirus guidelines as new infections hit a three-month high.
The country's disease control authority reported 1,226 new Covid-19 infections on Wednesday, the highest number since early May.
The figure has topped 1,000 on several days in Germany recently.
Health minister Jens Spahn said outbreaks have occurred in almost all regions, largely driven by travellers returning from abroad and people partying or having family gatherings.
“This is worrying, without doubt," he told Deutschlandfunk radio.
“And it can naturally lead to a new dynamic, if we don’t all now exercise caution."
In the early days of the pandemic the average age of people infected was 50. It is now 34.
Mr Spahn reiterated appeals to wear masks, stick to social distancing guidelines and not go overboard in social settings, while expressing scepticism about a new vaccine approved by Russia, the first country worldwide to do so.
“It’s not about being the first one,” he said.
“But it’s about having an effective, tested and therefore secure vaccine."
France takes its first steps out of Coronavirus lockdown
It comes as France's prime minister urged his people to "act collectively" to prevent a second wave of coronavirus.
Jean Castex warned the public that they were becoming careless following the easing of lockdown restrictions and another wave of the virus would be be "hard to control".
His comments came shortly before French health authorities said new daily infections were up by 1,397 over 24 hours on Tuesday, almost twice as much as the day before.
"If we don't act collectively, we expose ourselves to the heightened risk that the rebound in the epidemic becomes hard to control," Mr Castex said during a visit to a hospital intensive care ward in southern France.
