It comes as the nation's chief medical officer says it's likely there will be more cases of the coronavirus in Australia, following confirmation of four cases.

Coronavirus has killed 56 people in China and the city of Wuhan, the epicentre of the illness, remains in lockdown.

Professor Brendan Murphy says he will be sending out a message to GPs across the country on how to handle patients who present with symptoms of the deadly illness.

Three men are in hospital in Sydney after flying in from China, while another man in his 50s is being treated in Melbourne.

"There is no cause for general concern," Prof Murphy told reporters in Melbourne on Sunday.

"I would not be surprised if there are some more cases ... it's highly likely that we may see them some more.

"We are incredibly well prepared to isolate and deal with that."

Foreign Minister Marise Payne said the government would look to assist Australians with travel out of China, with several cities in lockdown as authorities try to contain the virus.

"We are seeking advice from the Chinese authorities on these restrictions and whether any options are available to international travellers," Senator Payne said.

"Our embassy in Beijing and our consulate in Shanghai are also working with international partners and the Chinese government to determine what support can be given to Australians on the ground."

Two of the men hospitalised in Sydney flew directly from Wuhan, a 53-year-old on January 20 and a 43-year-old two days prior. The third man, aged 35, arrived from the southern city of Shenzhen on January 6.

A fourth, also aged in his 50s, was Australia's first confirmed case of the virus after he touched down in Melbourne from Guangzhou on January 19.

Only the 53-year-old man is thought to have been contagious while travelling to Australia. He flew to Sydney on China Eastern flight MU749, and authorities are obtaining details of other passengers on that flight.

Meanwhile, passengers on China Southern Airlines flight CZ321 from Guangzhou to Melbourne on January 19 are also being contacted as a precaution.

Chinese authorities are scrambling to stop the spread of the deadly illness, restricting transport in the Hubei province including its capital Wuhan.

Coronavirus has been confirmed in other countries including Thailand, Japan, South Korea, Singapore, France, Malaysia and the United States.

Experts are still learning about the virus and Prof Murphy says it's important people arriving from Wuhan, as well as those in close contact with them, look out for symptoms of fever, cough, sore throat, vomiting and difficulty breathing.

Australians are being told not to travel to Wuhan or Hubei province.

Australian Associated Press