Swedish police have arrested a teenager after a fatal triple shooting in the city of Uppsala on Tuesday.

The shooter reportedly fled on a scooter following the attack in a hair salon in the centre of the city, triggering a manhunt.

Police confirmed on Wednesday that the person arrested for the shooting is under the age of 18.

All three victims were aged between 15 and 20 years old, Swedish police told a news conference, though the region's chief of police Erik Åkerlund said their identities have not been "100%" confirmed.

Police are investigating the possibility the deaths are related to gang crime, Swedish media reported.

One of those murdered at the hair salon is reportedly known to the police, local media said.

The victim was involved in a police investigation over a planned attack against a relative of gang leader Ismail Abdo, according to the reports. The person was never charged.

Abdo, nicknamed 'jordgubben' or 'the strawberry', is a well-known gang leader.

A new, violent chapter in Sweden's gang wars began when Abdo's mother was murdered in 2023 at her home in Uppsala, north of Stockholm.

Sweden has seen a wave of teenage gang crime in recent years, with suspects accused of a range of offences from vandalism to murder.

The Swedish government has proposed new legislation that would allow police to wiretap children under the age of 15 in an attempt to grapple with the problem.

In a pre-planned press conference on gang violence on Wednesday, the Minister of Justice Gunnar Strömmer suggested police would not need concrete evidence to conduct the wiretaps.

While he has acknowledged the proposals involve a major breach of privacy, Strömmer has suggested the measures are necessary to stop the recruitment of children as young as ten and 11 to gangs, Swedish media reported.

The government has also said it wants to tighten the country's gun laws.

The attack came on the eve of the Walpurgis spring festival, when large crowds are expected to descend on the streets of Uppsala, a university town north of Stockholm.

Known in Sweden as Valborg, university students gather in the city for champagne breakfasts, herring lunches and a raft race on the river.

There is a huge bonfire on the outskirts of the city planned for Wednesday evening.

Åsa Larsson, a local police chief in Uppsala and Knivsta, said that Swedes planning to visit Uppsala for its annual Valborg spring festival events, popular with students, should not change their plans.

However, visitors were urged to contact police if they spotted anything they were concerned about.

She said that there would be a large police presence across Uppsala in the coming days, but that there were "no guarantees" that further violence could be avoided.

Following the shooting, police officers cordoned off a large area near the hair salon.

"Everything happened so fast. It just went bang, bang, bang," a witness told Swedish channel TV4.

Another man said he was cooking at home when he heard "two bangs that sounded a bit like fireworks" going off outside on the street.

He told Swedish television he was "very surprised and scared" and shortly after "swarms of police and ambulances" started blocking off the street and telling people to move back.