Police said on Sunday that a 22-year-old woman was killed and five other people injured after one or more assailants opened fire at a rave in northern Switzerland.
Four men and another woman, aged between 24 and 27, suffered injuries ranging from minor to serious, police in the Swiss canton of Aargau said. All six victims were residents of Switzerland.
Numerous shots were fired early on Sunday at the rave on the grounds of the Aargau Racing Club in the cantonal capital Aarau.
Police said the motive was unclear and that they were conducting an intensive search for the perpetrator or perpetrators.
Authorities urged the public to avoid the area and appealed for witnesses to submit video and photographic material.
Organizers had expected around 3,500 people at the event, called the Aarauer Rave. How many people were at the venue when the shooting occurred was unknown.
The Aargau Racing Club expressed its condolences to the victims’ families.
The party “was overshadowed by a serious incident,” the club said in a statement, adding that emergency services had been immediately alerted.
Several witnesses told Swiss newspaper Blick that revellers initially mistook the burst of gunfire for fireworks.
One woman said someone then shouted “Everybody down!” and her group hid beneath the DJ booth.
“It was terrible,” the witness told Blick, adding that the shooting occurred immediately after the event had ended.
DJ Tekibo, who was performing at the event, described what had happened as “absolutely heartbreaking” in an Instagram story.
“Techno and raves are supposed to be a place for freedom and safety,” he wrote, adding that he had “lost an important friend” and would withdraw from performing for a period of time.
Police across the border in Germany were also involved in the wider search operation following the shooting. A spokesman for police in Freiburg described the cross-border involvement as routine but gave no details of the specific measures being taken.
The canton of Aargau borders Germany. Aarau lies about 40 kilometres west of Zurich.