Denmark’s prime minister wants to cull all minks in farms to minimise the risk of re-transmitting COVID-19 to humans.

Denmark’s State Serum Institute, which deals with infectious diseases, has found mink-related strands of the novel coronavirus in 214 people since June, according to a report on its website updated on November 5.

Meanwhile, one strain of the mutated coronavirus, which has prompted Denmark to cull its entire herd of mink, has been found in 12 people and on five mink farms so far.

Early this week, Prime Minister Mette Frederiksen said the government wants to cull all minks on farms to minimise the risk of the weasel-like mammals’ re-transmitting COVID-19 to humans.

“It is very, very serious,” Frederiksen said. “Thus, the mutated virus in minks can have devastating consequences worldwide.”

Health minister Magnus Heunicke said half the 783 human COVID-19 cases in northern Denmark “are related” to minks.

The development has prompted fresh measures to stem the spread of the virus; more than a quarter million Danes went into lockdown Friday in a northern region of the country where the mutated variation of the coronavirus has infected minks being farmed for their fur.

The coronavirus evolves constantly and, to date, there is no evidence that any of the mutations pose an increased danger to people. But Danish authorities were not taking any chances.

In seven northern Denmark municipalities with some 280,000 residents sport and cultural activities have been suspended, public transportation has been stopped and regional borders have been closed.

Only people with so-called “critical functions” such as police and health officials and different authorities are being permitted to cross municipal boundaries.

People in the region have been urged to to be tested. As of Saturday, restaurants must close, and school students from fifth grade and up will switch to remote learning Monday.

“We must knock down completely this virus variant,” Heunicke said on Thursday.

Denmark is one of the world’s main mink fur exporters, producing an estimated 17 million furs a year. Kopenhagen Fur, a cooperative of 1,500 Danish breeders, accounts for 40 percent of global mink production. Most of its exports go to China and Hong Kong.

According to government estimates, culling the country’s 15 million minks could cost up to five billion kroner ($785m). National police head Thorkild Fogde said: “It should happen as soon as possible.”

Denmark’s minister for food, Mogens Jensen, said 207 farms were now infected, up from 41 last month, and the disease has spread to all of the western peninsula of Jutland.

Last month, Denmark started culling millions of minks in the north of the country. The government has promised to compensate farmers.

The country has registered 52,265 confirmed COVID-19 infections and 733 related deaths.