Swedish police have arrested a teen suspect after three youths between the ages of 15 to 20 were killed in a shooting at a hair salon, authorities said Wednesday, with rising concern over gang violence in the Scandinavian nation.

Tuesday's shooting took place in broad daylight in the university city of Uppsala, a day before it hosted the Valborg spring festival, which draws more than 100,000 people for bonfires and celebrations in the streets, many of them students.

"One person has been arrested suspected of murder," police commander Erik Akerlund told reporters, with prosecutors saying the suspect was 16.