On New Year's Eve rioters at Connewitzer Kreuz in Leipzig hurled firecrackers and rocks at police officers.
The Mitteldeutsche Zeitung reported that the Connewitz neighbourhood in the German city is an Antifa stronghold.
Police warned the attackers over loudspeakers, Leipzig police said on Monday morning. But the attackers persisted, and police were forced to deploy water cannons against them.
Several people were arrested for severe public disorder and police confirmed that they were investigating the attacks.
Some 1000 people had congregated at Connewitzer Kreuz before midnight. After they had set trash cans and several items on fire, police moved in with water cannons to extinguish the fires.
During this operation, between 40 and 50 persons hurled bottles, rocks and firecrackers at the vehicles and the officers. The operation went on until about 1:30 early Monday morning.
Meanwhile, August Hanning, German Federal Intelligence Service (BND) chief from 1998-2005, has warned that the country will face an increased security threat “as long as we let people come into the country without identity papers”.
He told the weekly: “I wonder how long we can do this without major social upheavals,” adding: “Our society has become more colourful, but also ethnically more diverse – and thus more conflict-prone.”
German newspaper Bild am Sonntag quoted Hanning as saying: “As the terrorist attacks and attempted attacks in the last two years have shown, the security situation in Germany is very tense.
“Our security architecture needs to be urgently improved in order to meet new challenges. Otherwise it threatens to become very uncomfortable for us in Germany.”
Hanning tore into Angela Merkel’s open-border policy, noting the undeniable “link between internal security and efficient border control”.
“Nothing is worse than having a pessimist who is right,” he said. Hanning had warned of terrorist attacks and disruptions in society in the fall of 2015, unless the influx is better controlled.