Sebastian Toerstad,a high school student who drove past the embassy at the time of the blast,said: ‘There was a very thick layer of smoke ​on the street.

‘There was some damage to the entrance.’

Oslo police also confirmed to public broadcaster NRK that the blast occurred at the entry to the compound’s consular section.

Local Anna Gilbo told CNN: ‘I was watching TV and hear a loud bang while the whole house shook. There was a search going on for a while after the explosion which worried my friends and I,but it feels like the threat is over.’

Officers in white overalls were later seen working at the site.

Oslo Police said in a separate statement: ‘The police are in a dialogue with the embassy and there are no reports of any injured persons.’

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