A report from South Sudan says at least 20 Australians are being evacuated from the capital, Juba, following days of deadly clashes.
The United Nations says hundreds of people are believed to have died in fighting between between rival South Sudan army factions, which erupted on Sunday.
The United States and Britain have begun evacuating their citizens from the capital.
An Australian-South Sudanese man in Juba is accusing the Australian government of not doing enough to help its citizens stranded in the country.
Brisbane man Daniel John Barak had travelled to Juba to visit family over the festive period.
Mr Barak says the United States has begun evacuating its citizens from the capital via US Airforce planes, but the Australian government has not offered similar assistance.
"At this stage I've helped about 20 or 30 people out there, women and children," he told SBS World News Australia Radio.
He says he's most concerned for Australians caught in Jonglei state, which is currently inaccesible by road or air.
"Where they are right now it's very very critical and it's unknown (what their) situation at this time. There's no phone numbers. They're actually in the middle of nowhere. I have a few, more than 20 people in Juba, being evacuated today."
But a spokesman for the Department of Foreign Affairs says DFAT is providing consular assistance to Australian citizens in South Sudan.
"We are, through our High Commission in Nairobi, organising for daily welfare checks of the Australians in the country," says DFAT spokesman Justin Brown.
"We've done mass mailouts of our udpated travel advice. We have a smartraveler travel advice (website) which has been updated twice in the last couple of days in light of developments. And we're using those sorts of tools and relationships with our consular counterparts to maintain contact with the Australians in the country."
Mr Brown says any Australians in Juba should leave if they feel unsafe.
