SYDNEY/MELBOURNE • The fledgling travel bubble between Australia and New Zealand hit an early snag after 17 passengers who flew into Sydney on Friday caught a connecting flight to Melbourne, in an apparent breach of the rules.

In an effort to boost tourism, Australian Prime Minister Scott Morrison's government is encouraging visitors from New Zealand - which has crushed community transmission of Covid-19 - and says that they can enter the country without having to undergo hotel quarantine for 14 days.

But the quarantine-free travel corridor covers only New South Wales state, which is home to Sydney, and the Northern Territory.

The 17 passengers flew on to Melbourne within minutes of arriving in Sydney, and Victoria state Premier Daniel Andrews is not happy.

"We are not part of this bubble," he told reporters yesterday.

"I have written to the Prime Minister this morning and we're disappointed this has happened."

The authorities want to trace the passengers so they can be informed of local lockdown rules, he said.

Mr Morrison's acting Immigration Minister Alan Tudge said it had been widely understood that anyone arriving in Sydney from New Zealand would be free to travel on to other states - such as Victoria - that had not closed their borders to New South Wales.

He accused Mr Andrews, who is under pressure to ease a lockdown in Melbourne, of trying to create a distraction, the Australian newspaper reported.

The limited travel corridor falls far short of the bubble initially envisaged by Mr Morrison.

New Zealand is not yet reciprocating, and says anyone returning from a trip to Australia must quarantine for 14 days.

Indeed, Prime Minister Jacinda Ardern has urged New Zealanders to holiday at home instead.

Meanwhile, Victoria recorded a single case of the disease yesterday - the lowest daily number since early June - and no deaths.

State capital Melbourne, which has been the epicentre of the country's Covid-19 outbreak, is in its third month of a stringent lockdown and Mr Andrews is due to update plans to ease restrictions across the state today.

"We live in hope," Professor Brett Sutton, Victoria's chief health officer, said at a televised news conference. Earlier, when the coronavirus numbers were released, he said on his Twitter account: "One. One-der-ful."

Australia's federal government has been increasingly putting pressure on Mr Andrews to reopen the city and the state, with Health Minister Greg Hunt saying on Twitter yesterday that it was time to ease.

But Mr Andrews, whose Labor Party government is in opposition to the conservative Liberal Party at the helm of the federal government, said he would not get pressured.

"No one should be suggesting that... (we) are keeping the restrictions on any longer than they need to be," he said at the news conference.

"We aren't going to risk everything that Victorians have sacrificed."

In neighbouring New South Wales, Australia's most populous state, there were seven new cases of Covid-19, five of which were locally acquired and most linked to an outbreak at a childcare centre.

BLOOMBERG, REUTERS