Some 123 policemen were injured and some 86 people arrested as far-left extremists protested the eviction of a Berlin squat in what local authorities termed the most violent demonstration of the past five years.

An estimated 3,500 far-left radicals clashed with police in the Friedrichshain and Kreuzberg neighborhoods on Saturday and during the night that followed. They were opposed by some 1,800 security personnel. Police units came to the German capital from at least four different federal parts of Germany.

Other sources suggest there were up to as many as 7,000 rioters.

The protest in Berlin began near a squat on the Rigaer Strasse, constantly monitored by police as a popular leftist get-together location. The activists were banging pots and pans, and shouting: “Get the pigs out of the Rigaer!” Deutsche Welle reports.

They put out a banner, saying: “You have sold the entire city”, outside the Rigaer Strasse meeting point.

Rigaerstrasse 94 illegal eviction protest pic.twitter.com/Z9W3PAacak — fifthlookintern (@THIRDLOOKintern) July 9, 2016

As time went by, tensions with police escalated and rioters began throwing stones and bottles at law enforcers, then fireworks were fired at police as well.

At the peak of the clashes, the far-left demonstrators vandalized police cars and broke windows in a number of local stores.

Police repelled the activists with tear gas, and detained several of the most violent.

Although police declared the riot over by 11pm, there were reportedly clashes with law enforcement into the night, with paramedics busy providing medical assistance to blood-stained police officers and protesters alike.

The confrontation in Friedrichshain neighborhood, a cultural and nightlife center in the German capital, has been brewing for months.

The municipal authorities have been trying to clear the house on Rigaer Strasse of leftist squatters and their supporters, who often used anti-government rhetoric and have openly called for street violence over the last weeks.

The activists also strongly opposed the constant presence of police surveillance near the Freidrichshain meeting place.

Berlin Mayor Michael Müller, a center-left Social Democrat, proposed a peaceful option so that the residents of the Rigaer Strasse squat and the squatters got to the negotiation table. The mayor’s center-right Christian Democrat opponents argued the city is too soft on leftist radicals and their violent activities across Germany.