Tens of thousands of people took to the streets across Germany Friday to demand greater climate action, organisers said, but turnout for the "Fridays for Future" protests was smaller than in past years.

Demonstrators in cities including Berlin, Hamburg and Bonn called on Chancellor Olaf Scholz's government to exit oil, coal and gas and end fossil fuel investments.

Some held up signs that read "Save Our Future" and "Earth First".

Overall, more than 75,000 people rallied in around 110 towns and cities across the country, Fridays for Future said. 

Mass protests are "the most important way to achieve change", Carla Reemtsma, a spokeswoman for Fridays for Future Germany, told Bavarian broadcaster Bayerischer Rundfunk.

But a similar nationwide protest day five years ago attracted a far bigger crowd of 1.4 million people.