SYDNEY - Prime Minister Scott Morrison has insisted that a ban on travellers, including Australian citizens, entering from India is not racist but backed away from a threat to jail those who return.

The new rules, which began this week, bar entry to anyone who has visited India within the previous 14 days. Those who break the rules face jail terms of up to five years and fines of up to A$66,000 (S$68,000) .

The move has left thousands stranded and been condemned as racist, immoral and potentially illegal.

Mr Morrison said on Tuesday (May 4) that the ban was temporary and would be applied "compassionately and fairly". He told Channel Nine that it was "highly unlikely" that any travellers would be jailed for returning to Australia.

"The likelihood of anything like that occurring is pretty much zero," he said. "The sanctions are there, they exist, but they will be exercised proportionately and responsibly."

Mr Morrison said suggestions that the federal government was dismissing the safety of Australians in India were "absurd".

But the rules have been condemned by critics, who say they are unfair and treat India differently from other places that had heavy outbreaks such as the United States, Italy and Britain.

Australia's former race discrimination commissioner, Dr Tim Soutphommasane, said the federal government appeared to be applying "differential treatment" to India.

"There are different standards at play here, depending on which part of the world you're coming from," he told ABC News.

Calling the ban outrageous, the president of the Western Australia branch of the Australian Medical Association, Dr Andrew Miller, apologised on live television to Australia's sizeable Indian Australian community for the harsh punishments.

"It is not Australian to trap people overseas, and to suggest that a particular segment of the community should get fined for this is absolutely unacceptable and outrageous," he told Channel Nine.

Leaders of the Indian Australian community have also condemned the ban.

Dr Jagvinder Singh Virk, chairman of the India Australia Strategic Alliance, said 90 per cent of community members believed that the federal government would have sent rescue flights if people deemed as "real" Australians were trapped overseas.

"If there were 10,000 Australians with white skin, would they have done the same thing they are doing right now? No," he told The Sydney Morning Herald.

"People are feeling it's racist. What is happening to Australia?"

However, not all community leaders felt the move was racist, pointing out that it also affected expatriates in India who are not of Indian heritage.

India is one of Australia's largest source of migrants and has overtaken China to become the second-largest source of foreign-born residents. Last year, there were 721,000 India-born people in Australia, compared with 650,600 from China. In 2018-19, before the pandemic curbed travel, India was the largest source of permanent migrants to Australia, ahead of China, the United Kingdom, Philippines and New Zealand.

About 9,000 Australians are now in India, including some who went there to visit sick family members or attend funerals but are now barred from returning home.

The federal government has defended the ban, saying arrivals from India have led to a surge in cases of infections in quarantine.

The Health Minister, Mr Greg Hunt, said the ban was made with "a heavy heart but without hesitation".

"Those decisions are made to protect Australians, to protect against a third wave, to protect against a massive risk to Australia," he said.

The Labor opposition party said the government should not abandon Australians abroad and questioned why the ban had been imposed only on people in India.

"It is a disgrace," Labor MP Ed Husic told SBS News. "We should not be turning our back and leaving fellow Australians high and dry. We are better than this."

Australia currently has no cases of locally transmitted Covid-19. But minor outbreaks involving quarantine breaches - such as a recent cluster of five cases in Western Australia - can lead to sudden lockdowns of entire cities.

Some legal experts said the ban appeared to be unlawful because it breaches the right of citizens to return home. Some said the government should build safer quarantine facilities or assist Australians abroad to be vaccinated so that they can return.

The Australian Human Rights Commission expressed concern about the ban, saying the government must show it is not discriminatory. It called for a parliamentary inquiry into the measures.

The ban applies until May 15 and will then be reconsidered.