Cases of Covid-19 have increased in Sweden's main cities with the more contagious Delta having emerged as the dominant variant in the country, health authorities have said, though adding that infection levels nationally remain low.

According to a Reuters report, Sweden reported 1,855 new cases of Covid-19 last week, a 24 per cent increase compared to the previous week. Around a quarter of new cases were linked to travel abroad, the health authority has said.

"The number of cases nationally of Covid-19 continues to be at a low level, but an increase is seen in all metropolitan regions," the authority said in a statement, adding that 75pc of Sweden's adult population had now received at least one dose of vaccine.