Norway's government on Wednesday prolonged strict entry restrictions as part of an effort to stem the spread of more transmissible mutations of the coronavirus.
Justice Minister Monica Maeland said the moves were necessary due to "the infection situation in Europe" and would be in place until the end of February.
Exceptions included people involved in delivering key goods and services or employees in the health sector.
Norway requires a negative coronavirus test before arrival, registration of the purpose of the trip, and self-isolation for 10 days. Non-residents have been referred to designated quarantine hotels.
The government said it would tighten rules for venues used for self-isolation by foreign workers offered by some employers, citing violations detected by the Norwegian Labour Inspection Authority.
This sort of accommodation "must be approved in advance," Maeland said.
Gyms, sports centres
Outbreaks linked to virus strains detected in Britain and South Africa have resulted in the temporary closure of shopping venues in the greater Oslo region, including Oslo itself, as well as Norway's second-largest city, Bergen.
The temporary closures also affect gyms, swimming pools and sports centres. Exceptions include grocery stores, pharmacies and petrol stations.
People were urged to work from home where possible, avoid all non-essential travel and limit contacts outside their own household.
Health Minister Bent Hoie said that recent declines in the number of new cases had levelled off, but it was not clear if this was linked to the new virus strains.
Norway, a country of 5.3 million, has recorded about 65,300 coronavirus cases and 592 virus-related deaths.