Germany finds a suspected case of the variant.

The highly mutated new coronavirus variant known as Omicron is “very likely” to already be present in Germany, a regional health minister warned on Saturday.

At least one person who recently returned from South Africa has tested positive for Covid-19 and while the full sequencing of the variant that infected him has yet to be completed, several of the mutations already identified were typical of Omicron, Kai Klose, health minister of the western state of Hesse, said on Twitter. The variant was first detected in southern Africa.

Hesse contains the city of Frankfurt, a financial hub with a busy airport where two Lufthansa flights arrived from South Africa on Friday.

“There is a very strong suspicion, the person has been isolated at home,” Mr. Klose tweeted. “The #Omicron variant is with a very high probability already in Germany.”

The news prompted fresh concern at a time when Germany is already struggling to curb a brutal fourth wave of the pandemic that has produced tens of thousands of new daily infections — more than the country has had at any point in the pandemic. Hospitals across the country are struggling to accommodate the surge in Covid patients.

Germany is now one of several European countries with suspected or confirmed cases of the new variant. Belgium reported a case on Friday, in a traveler returning from outside southern Africa, and health officials in the Czech Republic said on Saturday that they were examining a suspected case in a person who spent time in Namibia, according to the news agency Reuters.

The full sequencing on the suspected case of Omicron in Hesse will only be completed early next week, said Sandra Ciesek, director of the Institute of Medical Virology at the University Hospital of Frankfurt.

The German government restricted travel from South Africa on Friday. As of midnight on Saturday, it will be designated a high-risk “variant region,” which means airlines are only allowed to transport German residents to Germany. All those who arrive have to quarantine for 14 days, even if they are vaccinated.