Police in Switzerland have arrested a suspect in connection with a shooting at a rave that resulted in one fatality and five injuries, authorities announced Monday. The incident occurred early Sunday morning in Aarau, a city in the northern canton of Aargau.

The arrested individual is a 43-year-old Swiss citizen, according to a statement from Aargau police. The arrest was made shortly before 1 a.m. Monday. Investigations into the motive are ongoing, and police currently believe the shooting was carried out by a single perpetrator. The location of the arrest was not specified.

The victim who died was a 22-year-old woman who sustained fatal injuries at the scene. Four men and one woman, aged between 24 and 27, were hospitalized with injuries ranging from minor to severe. Swiss police confirmed that all victims are residents of Switzerland. Italian Prime Minister Giorgia Meloni stated that the deceased woman and two other victims were Italian citizens.

Aargau police indicated they would hold a press conference on Wednesday and refrain from releasing further details until then. Public shootings are uncommon in Switzerland, a country with relatively widespread gun ownership. The rave was reportedly winding down when the shooting occurred at a horse racing track on the outskirts of Aarau.