Clashes between protesters and the police left over 90 policemen injured here on Wednesday, a spokeswoman of the Frankfurt police confirmed, Xinhuanet reported.
A total of 94 policemen were injured in clashes that erupted on Wednesday morning. Protesters took to the street, set ablaze seven police cars, smashed the windows of cars parked on the street and some buildings.
The official social media account of the Frankfurt Police Station reported that protesters threw cobblestones at police, who were forced to use water cannons.
The spokeswoman told Xinhua through telephone that 19 people have been arrested.
Riots were reported in several places in the city, where heavy security was deployed. Some 17,000 people took part in the demonstration against capitalists as well as the European Central Bank (ECB), which officially opens its new headquarters in Frankfurt.
Cueneyt Denizli, who represented a German trade union and took part in a demonstration at Roemerberg, a central square of the city, expressed his solidarity with the Greek people.
In an interview with Xinhua, he said that the austerity policy for Greece should be abolished and the Greek people should have the right to choose their own way of development.
The demonstration, which gathered some 10,000 people, started in the afternoon and featured speeches against the the policies of the ECB. No damages or clashes were reported during the demonstration at the square.
The demonstration was called by a group named Blockupy, which included people from various European countries who are against austerity.