A manhunt is under way after a 22-year-old woman was killed and five others injured in a shooting which reportedly took place at a rave in northern Switzerland.

The woman died at the scene in Aarau, police said. Those injured were four men and a woman aged between 24 and 27, all of whom are in hospital with injuries “ranging from minor to severe”.

The force confirmed the shooting happened at an event at a horse racing track in Aarau, where a rave was taking place into the early hours of Sunday.

Police said the perpetrator’s identity and possible motives were unknown, as were the “exact circumstances” of the incident in the town near Zurich.

Local media reported that the force was alerted to the shooting around 02:30 local time (01:30 BST).

Swiss DJ Tekibo, who was performing at the annual techno event, said he had lost a friend in the incident.

Writing on Instagram, he said he was “still trying to process what happened”.

Aargau Racing Club said the rave was “overshadowed by a serious incident”. It also thanked emergency services for their response.

According to the organisers’ website, up to 3,500 people were expected to attend.

Police asked witnesses to submit photographs and video from the scene.

An area around the racing track, the town’s swimming pool and sports field has been cordoned off, with the public urged to stay away.

A large contingent of officers has also been deployed beyond Aarau “as a precaution”, Aargau Cantonal Police said. An AFP journalist reported seeing armed officers deployed on the highway up to 30km (18 miles) from the site of the shooting.

Aarau is located some 46km west of Zurich and is home to approximately 23,000 people.

Images from Aarau early on Sunday showed a heavy police presence in the area, with an armoured vehicle seen blocking a road. Armed police and officers in riot gear could be seen patrolling the streets.

In addition to police and fire officials, the regional disaster response unit (KKE) was deployed, according to broadcaster SRF.

It also reported that a Swiss Army helicopter could be seen surveying the area in the early hours.

Switzerland has one for the highest rates of gun ownership in Europe, although violent shootings are rare and tighter controls were introduced in recent years.