The Australian state of Victoria added the Melbourne Cricket Ground (MCG) to a growing list of coronavirus hotspots and ordered thousands of football fans to self-isolate as it reported six new locally acquired cases on Wednesday.

An infected person was among about 23,400 people who attended an Australian Football League (AFL) match at the MCG on Sunday, state officials said as the cluster of infections in Melbourne grew to 15 in the past 3 days.

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The 100,000-capacity former Olympic stadium was included on the list of virus-exposed locations in Melbourne with dozens of new venues including supermarkets, cafes and pubs.

Victoria on Tuesday reinstated restrictions on gatherings and made masks mandatory in restaurants, hotels and other indoor venues until June 4, while New Zealand paused its quarantine-free travel with the state for three days.

The new cases have been traced back to an Indian variant of the virus found in an overseas traveller who had completed quarantine, but officials have not found how the coronavirus spread into the wider community.

Australia has successfully tackled past outbreaks with swift contact tracing, local shutdowns and tough social distancing rules helping keep its COVID-19 numbers relatively low compared with other developed countries. It has recorded just over 30,000 cases and 910 deaths since the pandemic began.

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A second wave of COVID-19 hit Victoria late last year resulting in the state accounting for about 70% of total cases and 90% of deaths in Australia. That outbreak was only brought under control after a long and strict lockdown.