New coronavirus restrictions announced for Melbourne as Whittlesea cluster grows to nine

Youths gather in the Tel Aviv on 19 April 2021 after authorities announced that face masks for Covid-19 prevention were no longer needed outside

New Zealand's travel bubble with Victoria will be paused while the source of infection of the five cases announced in Melbourne in the last two days is investigated, Covid-19 Response Minister Chris Hipkins says.

The cases come after four locally acquired cases emerged on Monday - a man in his 30s, a woman and man in their 70s and a pre-school aged child.

"This virus is very bad in the way that it can spread", Chief Health Officer Brett Sutton told ABC Radio Melbourne on Tuesday.

Anyone experiencing symptoms is advised to get tested immediately.

Professor Sutton confirmed the COVID-19 variant in the Whittlesea outbreak is B1617, which was first identified in India in October a year ago.

Chief health officer Brett Sutton said he was concerned about commuters who travelled via train with an infectious case earlier this month. "You can be very unlucky with rare cases that are particularly infectious that have been to lots of places and transmit it to lots of people".

Professor Sutton said there was "no immediate link" between today's case and that of a Wollert man who tested positive after leaving hotel quarantine in South Australia earlier this month.

Professor Sutton said genomic sequencing had also determined they were infected with the B.1.617 mutation, also known as the Indian variant.

Players and staff at Australian Football League side Western Bulldogs were isolating until they return negative COVID-19 tests, the team said, after one of the club's staff went to a shopping centre deemed an exposure site by authorities.

On Tuesday, authorities said they expected the list of exposure sites to grow over the coming days.

There is new advice for people who attended the Highpoint Shopping Centre exposure site, with CCTV footage allowing the Department to provide more specific information on which individual stores the positive case visited.

One of the five confirmed cases attended Broadmeadows Hospital on May 21.

Private gatherings in the home will now be limited to five per day.

It is not now listed as a public exposure site as the Department has access to records of everyone who attended the hospital.

Prime Minister Jacinda Ardern said today that New Zealand health officials were "in close contact" with their counterparts across the Tasman, as the state of Victoria imposes new restrictions.

"Victorians visiting regional Victoria from Melbourne will also need to wear a face mask when indoors, even when outside metropolitan Melbourne, unless an exemption applies".

Mr Merlino said a mask was required for everybody aged 12 and over.

A list of COVID-19 areas of concern in Greater Melbourne can be found via the ACT Government's COVID-19 website.