The first message to the police before 2.30 was that there was a match at the stadium in Brenneriveien in Oslo.
"But when we arrived, it turned out that it probably stole the knife." Immediately after the accident, NTB's Marita Aune operations manager said.
Two criminals are transferred to the hospital. Aune does not want to provide sex or age.
"Both are injured and classified as seriously injured," NTB said.
According to TV 2, both of them knew when the emergency services had arrived, but they lost consciousness when they entered the ambulance.
Three possible insults
Information police have pointed out that there may be a third person who is stabbed or injured.
"It is difficult to say why the person was no longer there when the police arrived, and we can not be certain about the role of the person in the matter, but he is considered a criminal because he has to be wounded .
She says she does not assume the injured is a perpetrator.
Currently there is no active search for perpetrators and offenders.
The event was held at Blue Out in Grünerløkka.
He added that "there are many witnesses to the case," adding that the police were closed and separated so that they could conduct necessary investigations.
"It was night on Sunday, there were a lot of people inside and outside the venue, we can get enough.
Police worked on-site with an on-the-spot investigation as well as the fact that the offender was on the way to the place at 4.40. Video surveillance will also be reviewed.
The police can not control all possible weapons.