Three people were killed and several injured after being shot in eastern Sweden on Tuesday.

Swedish police said yesterday that multiple people in the city of Uppsala were found with injuries that resembled gunshot wounds.

'Three people are confirmed deceased following a shooting,' officers said in a statement, adding they had opened a murder investigation. The identities of the dead have not yet been established.

The force added that they had received calls from members of the public who said they had heard noise that sounded like gunfire close to Vaksala Square in the centre of the city.

Police spokesman Magnus Jansson Klarin said: 'We have received several reports of gunshots in the area. We're trying to get a better idea of ​​what happened. This is a serious incident and a very large-scale operation.'

A large area was cordoned off and several investigative measures were underway at the scene, he added.

It is unclear whether anyone has been arrested following the incident but police said they had received information that a masked person left the scene on an electric scooter.

'Whether this person is a perpetrator or a witness, or someone who has some connection to the incident, it is unclear at this time,' a spokesperson for the force said.

Police said it was investigating the shooting as a homicide and that it had no information about the incident being a terror or hate crime at this point. 

An anonymous witness who spoke to Swedish news outlet SVT said they heard five gunshots ring out, before seeing people running in different directions and hiding. 

Witnesses who spoke to Sweden's public service radio, Sveriges Radio, said they heard gunshots near a barber shop in a central square, not far from the train station. 

One local told Aftonbladet: 'There was a shot and then I heard screams. Then it took about 10 minutes before the police got there. It must have been on the street from what I could see.'

Another witness, who had been at a nearby playground with his son, said: 'At first I didn't understand what was making that loud noise, but when I saw and heard the police helicopter a little later and talked to other parents who had gone there and looked, it dawned on me.

'I don't feel like I'm scared myself, but of course it gets nasty when it happens here.' 

The Minister of Justice Gunnar Strömmer commented on the incident and described it as 'extremely serious'. 

The Swedish Transport Administration stated that train traffic to and from Uppsala was temporarily stopped at 5:30pm, but by 6pm, it was back up and running.

The shooting happened on the eve of the Walpurgis spring festival, which which draws more than 100,000 people to the city.

'We see no danger to the public here and now, I want to be careful to emphasise that since many people are out celebrating,' Klarin said.

'People should not be afraid to come tomorrow,' he added.

'There are 100,000 to 150,000 people expected in Uppsala for Valborg tomorrow, and there are already a whole lot here today.'

It comes after ten people were killed in February in the Swedish city of Orebro in the country's deadliest ever mass shooting, in which a 35-year-old opened fire on students and teachers at an adult education centre.

The Nordic country's right-wing government subsequently said it would seek to tighten gun laws.