Swedish authorities are investigating a large fire that broke out at the Portuguese embassy in central Stockholm on Wednesday.

The fire is being treated as arson according to the Portuguese Foreign Minister Augusto Santos Silva.

"Everything points to an isolated act from a disturbed person who demanded to speak with the official in charge of the portuguese consular service. His demand was accepted but before they could speak he acted criminally by starting a fire and then running away." said Silva in a televised statement from Lisbon.

According the police 14 people received medical assistance after the fire and two were taken to hospital for smoke inhalation though none are believed to be in a serious condition.

Police have now arrested a man linked to the investigation but will not comment on his role.