Swiss authorities have arrested a suspect in connection with a fatal shooting at a rave near Zurich that killed one woman and injured five others. The shooting occurred in the early hours of Sunday at the Aarau racetrack, where an annual techno party was taking place with some 3,500 attendees.

The deceased was identified as 22-year-old Maria Spinelli, an Italian woman residing in Switzerland, who died at the scene. Among the injured were five individuals aged between 24 and 31, including a German woman. The injuries ranged from minor to serious. Italy’s government confirmed that two other Italians sustained light injuries and that embassy officials were closely monitoring the investigation.

Swiss police initially launched a manhunt for the shooter or shooters following the attack. At the time, law enforcement officials reported being unsure about the number of assailants and how they fled the scene. Investigators indicated that evidence showed the use of two different firearm calibers, potentially from a pistol or submachine gun and an assault rifle.

On Monday, police confirmed the arrest of a 43-year-old Swiss national suspected of acting alone. Authorities have not disclosed further details about the suspect or motive and stated that no additional information would be released before Wednesday afternoon. Officials emphasized that investigations into the sequence of events and background circumstances are ongoing.

The shooting at the Aarau rave is a rare occurrence in Switzerland, a country known for widespread gun ownership but infrequent gun violence. The last notable mass shooting happened in 2001 in the canton of Zug, when a gunman killed 14 parliament and local government members before taking his own life.

Local police have kept the area around the racetrack sealed off since the incident, while continuing to interview witnesses and gather evidence. The case remains under active investigation as authorities seek to clarify the motives and circumstances surrounding the attack.