COPENHAGEN (AFP) - Denmark's health authorities said on Sunday (Dec 5) that the country had seen a "concerning" jump to 183 confirmed cases of the Omicron variant of Covid-19.

This means confirmed cases increased by more than 10 times, from 18 confirmed and 42 suspected cases on Friday, according to data from the SSI public health institute.

The European Centre for Disease Prevention and Control (ECDC) had previously tallied just 182 cases across all of the European Union, plus Norway and Iceland.

Denmark is one of Europe's most advanced countries in sequencing of coronavirus variants.

It often detects more cases more quickly than its neighbours, which does not necessarily indicate higher rates of infection.

The SSI chief said the increase in Omicron cases was nevertheless "concerning", adding that "there are now chains of infection where the variant is found in people who have not travelled abroad or been in contact with travellers".

Also on Sunday, the ECDC said Omicron had been reported in 17 countries in its region.

"The majority of confirmed cases have a history of travel to countries in Africa, with some having taken connecting flights at other locations between Africa and Europe," said the ECDC on its website before the Danish announcement.

Nevertheless, "several EU/European Economic Area countries (Belgium, Germany, Spain) detected cases without an epidemiological link to areas where community transmission of the Omicron variant is documented or presumed", it added.

"This indicates that undetected community transmission could be ongoing in these countries."