Earlier in the day, a spokeswoman for Blockupy activist group that organized the protest said that Frankfurt police used tear gas grenades and water cannons as it attempted to disperse the anti-austerity crowd.
"Main injuries are from tear gas, and someone was injured when falling down," the spokesman for the Fire Department, which is responsible for emergency rescue operations, said. There have been no serious injuries, he added.
Detailed statistics will be available at the end of the day on the department's Twitter account.
Earlier on Wednesday, somewhere from hundreds to thousands of protesters, according to officials and Blockupy, gathered ahead of the opening of the $1-billion European Central Bank headquarters in Frankfurt to protest the European Union's austerity policies.
Additional demonstrations are expected to take place in the city later in the day.