Health officials say the newly discovered Omicron variant may be fuelling the surge, although it isn't clear how many of the new cases it accounts for.

Some 8,500 Covid infections have been registered in the last 24 hours.

South Africa was the first country to detect the highly mutated new variant which was announced last week.

The United States has identified its first Omicron case in someone who had returned to the country from South Africa.

Many questions about the new variant remain to be answered, including whether it is more transmissible and how much protection current vaccines provide.