Australia's second most populous state of Victoria will enter a one-week Covid-19 lockdown forcing its near seven million residents to remain home except for essential business as authorities struggle to contain a highly infectious outbreak, Reuters reports.

“We're dealing with a highly infectious strain of the virus, a variant of concern, which is running faster than we have ever recorded,” Victoria state Acting Premier James Merlino told reporters in Melbourne.

“Unless something drastic happens, this will become increasingly uncontrollable.”

Merlino said contact tracers have identified more than 10,000 primary and secondary contacts who would need to quarantine, test and self isolate, adding “that number will continue to grow and change”.