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.

Italian national Maria Spinelli died at the scene in Aarau on Sunday morning, police said. Four men and a woman, aged between 24 and 27, were in hospital with injuries "ranging from minor to severe".

Italy's prime minister Giorgia Meloni said she was confident Swiss authorities would "shed full light on what happened and find anyone responsible".

Aarau cantonal police spokesman Michael Leupold told a news conference on Sunday afternoon that officers were "still in the midst of the operation" and had no leads on who may have been behind the shooting.

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.

The force said it had received an initial report of shots fired at the Schachen race track at around 02:30 local time (00:30 GMT).

Leupold reiterated that the police were conducting a large-scale, nationwide manhunt for the perpetrator, but said that there were currently no leads on whether it was one person or multiple individuals.

They were not believed to be in Aarau anymore, he added.

The investigation is being carried out in co-operation with Freiburg police, German news agency DPA reported.

Italy's foreign ministry said in a statement that it was sending officials to Zurich "to closely follow the investigation".

It added that two other Italians "were slightly injured and have already returned home".

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 the police investigation.

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", the cantonal police said.

Aarau, home to approximately 23,000 people, is less than 40km 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.

The police said there was still "a strong force" at the crime scene as well as around town "to make sure that if any new information [gets in] we could respond".

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.

The last major shooting occurred in 2001, when 14 members of the parliament and local government of Zug, near Lucerne, were killed by a gunman who then took his own life.