Belgium said Friday it has detected the first announced case in Europe of the new COVID-19 variant, in an unvaccinated person returning from abroad.

"We have a case that is now confirmed of this variant,"  B.1.1.529, first detected in southern Africa, Health Minister Frank Vandenbroucke told a media conference.

The infected person tested positive on November 22 and had not had COVID-19 before, he added, without giving further details.

A leading Belgian virologist, Marc Van Ranst, tweeted that the person had returned from Egypt on November 11.

Vandebroucke said: "It must be repeated that this is a suspect variant -- we don't know if it is a very dangerous variant."

He noted, however, that "as a precaution" Europe was stopping flights from southern Africa. 

"So, total precaution but don't panic," he said, adding that Belgium's COVID-19 risk assessment group was analysing the situation. 

The variant is blamed for a recent surge in infections in South Africa.

Just hours after it was announced, Britain said all flights from South Africa and its neighbours Namibia, Lesotho, Eswatini, Zimbabwe and Botswana would be prohibited from Friday.

A slew of countries are following suit, including France, Germany, Italy and Singapore and Malta.

In Malta, the ban comes into effect as of 12am between Saturday and Sunday.