Swiss police launched a manhunt Sunday after a 22-year-old woman was killed and five people were injured, in a shooting at a rave party in the northern canton of Aarau.

All the victims are Swiss residents and in their 20s, police said, adding that there was a ⁠large ⁠deployment and large areas of the town cordoned off. They appealed to the public for any images of the incident.

A witness told local daily Blick that shots were fired around 2:30 a.m. Sunday morning, and that he tried unsuccessfully to reanimate a woman bleeding from a ⁠gunshot wound.

Police said a 22-year-old woman died from her injuries at the scene. They have increased their presence beyond ​the town – about 50 kilometers west of Zurich – as ​a precaution.

An army helicopter was monitoring from overhead, Swiss state broadcaster RTS reported.

The organizers' ⁠website ‌advertised ‌the event as a techno party ⁠at a covered horse racetrack, ‌with 3,500 people expected to attend.

Switzerland has one of ​the highest rates of ⁠gun ownership in Europe although violent ⁠shootings are rare and it approved tighter gun ⁠control rules ​in 2019.