An explosion occurred early Monday morning in Cologne's city center, damaging a building near the Vanity nightclub on the Hohenzollernring.

The area between Rudolfplatz and Friesenplatz has been cordoned off by police, who are conducting a major operation.

Initial reports suggest that one person may have been slightly injured, possibly suffering from a blast trauma, but no serious injuries have been confirmed.

The cause of the explosion remains unclear, and authorities are investigating, including reviewing surveillance footage that reportedly shows a person leaving a bag at the scene.

Residents are advised to avoid the area as investigations continue.