The Berlin Fire Department responded to an alarm at the Reichstag building in Berlin-Mitte early this morning, deploying approximately 80 firefighters. The incident, which began around 5:15 AM, was triggered by a gas detector indicating the release of a small quantity of a hazardous substance in a large room. While the exact cause is still under investigation, a cleaning concentrate has been found, suggesting a possible over-concentration of cleaning agents as the culprit. The building was secured by police around 7:30 AM, and no injuries were reported. The emergency response caused temporary traffic disruptions and rerouted bus lines.