Besides Frankfurt - Germany's financial hub - there were incidents of violence in Berlin, Cologne and Hamburg cities as well
Rioters looted shops in central Frankfurt late on Saturday and clashes erupted with police there and in other German cities after largely peaceful mass protests over the cost of living.
Thousands earlier joined the demonstrations organised by the campaign group Gen Z regelt - meaning "Gen Z takes charge" - to protest against underfunding in schools, the high cost of living, public spending cuts and military service.
The unrest in Germany follows similar youth-led mass protests in France, where more than 320,000 people also demonstrated on Saturday.
A large section of Frankfurt's main shopping street was closed off by police, AFP news agency reported. A police spokesperson said many arrests were made in the city.
Authorities in Frankfurt, Munich and Berlin reported as many as 18,000 protesters, roughly half of what the organisers had estimated on their website.
Source: The Star