Coronavirus has been detected on another mink farm in the province of Noord-Brabant, bringing the number of infected farms to 26.

The infection was picked up by an early warning system introduced in the industry, in which bodies of dead animals are tested weekly for the virus, Omroep Brabant reported.

All 3,500 adult female mink on the farm in Oploo, in the municipality of Sint Anthonius near Helmond, will be exterminated as a precaution. More than a million mink have been killed since the virus was first found in May. Several farm workers are thought to have been infected by the animals.

Meanwhile, volunteers at the Pieterburen seal sanctuary in northern Groningen have gone into quarantine as a precaution after one of their colleagues from Switzerland tested positive for coronavirus.

The sanctuary has been closed to visitors from Monday. Anyone who bought tickets in advance will be refunded.

‘All our colleagues are needed now to ensure the seals can be looked after in our rehabilitation centre,’ said the organisers in a statement.