A manhunt is under way after a 22-year-old woman was killed and five others injured in a shooting at a rave in 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”.

Organisers and performers said the shooting happened at a techno rave being held at a horse racing track in the town, which is located some 46km (29 miles) west of Zurich.

A police spokesperson told Swiss media on Sunday afternoon that they had “no concrete leads”, having earlier said the shooter’s identity and motives were unclear.

It is unlikely that they are still in Aarau, spokesman Bernhard Graser told Swiss newspaper Blick, but there is “no imminent danger”.

The force said it had received an initial report of shots fired at the Schachen race track at 02:30 local time (01:30 BST).

A DJ who was due to perform until the scheduled end of the event at 02:00 said the incident occurred “straight after our set”, in a post on social media.

Another performer, DJ Tekibo, said he had lost a friend in the incident. He wrote on Instagram that he was “still trying to process what happened”.

Olivier Grein, whose firm Agency Events AG organised the event, said the company was “shaken” and would do all it could to support police.

An eyewitness told Blick that he “suddenly heard the gunshots” minutes after the music stopped at 02:30, initially believing they were fireworks.

He said he was told to hide by a man and a woman, the latter of whom was then shot.

Organisers had expected up to 3,500 people 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, home to approximately 23,000 people, is less than 40km (25 miles) from the border with Germany, where local media reported police were supporting Swiss forces.

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.