The Omicron variant of COVID-19 has probably arrived in Germany, a minister in the western state of Hesse said on Saturday after mutations were found in a passenger arriving from South Africa.

"Last night several Omicron-typical mutations were found in a traveller returning from South Africa," tweeted Kai Klose, social affairs minister in Hesse, home to Frankfurt airport, Germany's biggest hub and one of Europe's busiest airports.

He added that a full sequencing of the variant was being carried out and that the person was isolating, and he urged anyone who had travelled from South Africa in the last few weeks to limit contacts and get tested.

The new variant has been found at a time when Germany and many other European countries are grappling with a surge in coronavirus cases.

Germany recorded 67,125 new coronavirus cases on Saturday, the Robert Koch Institute for infectious diseases said, and more than 100,000 people have died with COVID-19.

Germany is declaring South Africa a virus-variant area, meaning airlines are allowed to fly only Germans to Germany from South Africa, a source told Reuters on Friday. Even those who are vaccinated must spend 14 days in quarantine.

Earlier, Dutch health officials said they had detected 61 COVID-19 cases among people who flew from South Africa on Friday and are trying to establish whether any were infected with the Omicron variant.