Australia's Victoria state authorities said they had detected the highly infectious Delta Covid-19 virus variant for the first time in the latest outbreak in Melbourne, stoking concerns of a major spike in cases, Reuters reports.

The Delta variant, which has been classified by the World Health Organisation (WHO) as among the four Covid-19 variants of concern due to evidence that they spread more easily, likely caused the latest devastating outbreak in India.

“It is a variant of significant concern,” Victoria state Chief Health Officer Brett Sutton told reporters in Melbourne. “The fact that it is a variant different to other cases it means it is not related, in terms of transmission, with these cases.”

Sutton said the new variant had not been linked to any sequenced Covid-19 infections across Australia from hotel quarantine or elsewhere.