Campers have been told to leave a North Stradbroke Island beach by 4pm (AEST) or face being removed as a large bushfire burns nearby.
Queensland authorities want to have Main Beach cleared of people before they close the only road out.
"We are asking people to evacuate. However, we would suggest if you aren't removed from that area by four o'clock today you will be forced to evacuate," a police spokeswoman told AAP.
The fire, which was set off by lightning, has been burning in thick bushland for days.
It's not threatening lives or property, but authorities are concerned about an expected wind change on Wednesday afternoon.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
About 900 campers could be at risk if the fire changes direction, they say.
A massive exodus began earlier on Wednesday and many people are arriving in the town of Dunwich.
Ferries and barges will take the holidaymakers back to the mainland from there.
A Stradbroke Ferries manager told AAP they could not comment because they were too busy organising the evacuation.
