The Red Cross says on Twitter that it treated around 15 people for burns caused by flares during the cup final at Ullevål between Brann and Lillestrøm.
A total of 32 people out of 27,000 spectators received help from relief corps volunteers, according to the Red Cross.
– The messages I received from our volunteers are that the surveillance was calm, considering that so many people were present in Ullevaal, corps commander Anahita Panjwani told the Oslo Red Cross.
Oslo Police Operations Director Alexander Østerhaug told TV 2 they had been made aware of the incident.
– What we do know is that the injured were treated on the spot by health personnel. We have received no feedback on the degree of damage, says Østerhaug.
The operations manager does not know if anyone has been taken to hospital. TV 2 has been in contact with Oslo University Hospital, which will not say whether it has taken in the injured.
Oslo police will now investigate the matter further.
– It is not allowed to use flares in Norwegian football stadiums, so here there will be another dialogue between the police and the organizer to follow up what happened, says Østerhaug.
Apart from the incident with flares, police say the cup final was calm and peaceful. Before, during and after.
Brann emerged victorious in the cup final with 2-0 over Lillestrøm.