Australia recorded the deadliest day of the Covid-19 pandemic on Wednesday, and the largest daily increase in positive Covid-19 cases in three days, so it dispelling hopes that the second wave gripping the state of Victoria might stabilize.

Victoria has reported 21 deaths – two more than the previous deadliest day earlier this week – and 410 new cases in the past 24 hours, ending three consecutive days with new infections under 400.

An infection cluster in Melbourne, Victoria’s capital and Australia’s second-largest city, forced authorities last week to impose a curfew, tighten restrictions on people’s daily movements and order most of the country’s economy to shut down.

The national figures for the last 24 hours have not been released but outside of the two largest states in Victoria and New South Wales (NSW), the virus has been effectively eradicated.

Authorities in NSW are trying to trace infections linked to a new cluster at a Sydney school, which has raised fears of a wider community spread than was previously known in Australia’s most populous state.

Australia has reported more than 22,000 infections and 352 deaths from Covid-19.