Nearly 600 officers raided numerous buildings, including the clubhouse of street gang United Tribuns, in a raid investigating weapons violations and tax evasion, in part involving the operation of gaming machines.
Traffic along the street where many of the raids took place, Eisenbahnstraße, was blocked off during the day, and officers also shut down areas around the central train station where further buildings were searched.
Officers seized two presumed dangerous pistols and ammunition, one non-lethal pistol, a baton, brass knuckles and several hundred grams of various narcotics. There was one arrest in connection to the discovery of the drugs.
Details of the suspects were not released by police.
Eisenbahnstraße is known as a dangerous area for drug crime in the Saxon city. It has been dubbed by German media as "the most dangerous street in Germany", according to Die Welt. Last year in June, a shootout took place between the United Tribuns and Hells Angels members there, in which one person was killed.
Police asked for calm and understanding during the raids on Thursday, taking to Twitter to reassure residents of Leipzig that there was no terror threat.
(1/3) Polizeieinsatz in #Leipzig, mehrere hundert Einsatzkräfte durchsuchen Objekte in der Innenstadt, kein Anti-Terror-Einsatz!- Polizei Sachsen (@PolizeiSachsen) January 12, 2017
Officials are investigating whether the weapons and ammunition were brought to Leipzig through organized crime groups.