The government said on Wednesday it would cull all minks in the Nordic country to prevent human contagion with a mutated coronavirus, which authorities said could be more resistant against future vaccines for people.

The move to cull up to 17 million animals, which could cost the state more than $800 million, has prompted some lawmakers to demand to see the evidence behind the decision.

"We are asking to have it (the evidence) sent over, so we can assess the technical basis," a spokesperson for the Liberal Party told broadcaster TV2 on Wednesday.

Outbreaks at mink farms have persisted in Denmark, the world's largest producer of mink furs, despite repeated efforts to cull infected animals since June.

Municipalities in northern Denmark, home to most of the country's mink farms, will face restrictions on movement across county lines, while restaurants and bars will be forced to close, mayor of Vesthimmerland Municipality, Per Bach Laursen, told Reuters.

The ministry of health declined to comment but is expected to announce a range of new measures aimed at containing the new virus strain later on Thursday.

In a report published on Wednesday, the State Serum Institute (SSI), the authority dealing with infectious diseases, said laboratory tests showed the new strain had mutations on its so-called spike protein, a part of the virus that invades and infects healthy cells.

That poses a risk to future Covid-19 vaccines, which are based on disabling the spike protein, SSI said.

"There is a risk that vaccines targeting the spike protein will not provide optimal protection against the new viruses occurring in mink," it said.