The four who have now been arrested are men between 27 and 43 years old, the police write on their website.
Eleven men have been sentenced to prison terms of between two and seven and a half years.
Eight judgments have also been tested in the higher instance, the Court of Appeal, but there the judgments have not yet been passed.
A total of 23 people have been detained after the violence that took place in Sveaparken in Örebro, of which four were minors who were then released again.