A freight train carrying 200,000 litres of sulphuric acid has derailed in Australia, with a two-kilometre exclusion zone around the remote accident site in Queensland in place Monday.

Aerial photographs showed wagons lying on their side strewn around the area, which has also been hit by heavy rain and flooding  

Police said there had been a minor leakage of sulphuric acid and spillage of diesel fuel from the accident which occurred on Sunday.

"One locomotive and all 26 wagons are on their side following the incident," said a spokeswoman for Queensland Rail.

Police declared an emergency at the crash site 20 kilometres (12 miles) east of the town of Julia Creek, which has been difficult to access due to flooding.

Inspector Trevor Kidd told the Australian Broadcasting Corporation on Monday that assessments were being made as to whether the spill had affected the environment, but stressed it was in a remote location.

Sulphuric acid is corrosive and can cause severe burns when it comes into contact with the skin.

Queensland Rail said its assessors had not been able to investigate what caused the derailment because roads in the region were cut off due to flooding.

Three men are understood to have sustained minor injuries in the crash.