“We've come under attack by groups of left-wing extremists in several locations,” a police spokesperson said. “We have to react decisively in order to prevent anything worse from happening.”
Several groups of left-wing activists tried to break through barriers erected to restrict access to a square in Cologne's historic center where far-right groups were rallying to protest what they call an “immigrant invasion” and the “Islamification” of Europe.
According to eye witness reports, at least two of the demonstrators involved in the scuffle were arrested.
Police said that one officer was hit by firecrackers and injured in the face.
Some 3,000 police have been deployed in the city for the three-day “congress.” The organizers of the event, the far-right nationalist group Pro Köln (For Cologne) say they expect up to 1,500 sympathizers.
Several thousand counter-demonstrators are expected to take part in peaceful protest events around the city.