Sydney (AFP) - Tens of thousands of litres of sulphuric acid may have leaked from a freight train that derailed in Australia?s outback, police said Tuesday.
Queensland authorities also quadrupled the amount of acid the train was carrying when it crashed near the town of Julia Creek to 819,000 litres (216,357 gallons), equivalent to about one-third of an Olympic swimming pool.
The freight train, which lies corkscrewed over the track, was originally thought to be transporting 200,000 litres when the locomotive and 26 wagons derailed on Sunday.
"Assessments to date indicate that one of the carriages has likely ruptured and it is possible that up to 31,500 litres of acid has leaked out," police said in a statement.
"No other ruptured carriages have been identified as leaking at this stage."
Sulphuric acid is corrosive and can cause severe burns when it comes into contact with the skin.
Authorities have ordered a two-kilometre (1.3 mile) exclusion zone around the area, which is about 300 kilometres east of Mount Isa and currently difficult to access due to floodwaters. The measure is expected to be in place for at least 48 hours.
Police said initial testing indicated that the nearby Horse Creek waterway had not been affected by any leakage.
They previously said the site's remote location in central Queensland was a plus, given it was far from major waterways and infrastructure.
But it could take weeks to clean up the wreckage.
"There is heavy mud and unstable ground between the road and where the incident site is so it's a difficult area to move around in," Mount Isa police inspector Trevor Kidd told Channel Seven television.
Parts of Queensland have endured recent flash flooding, cutting off highways, leaving motorists stranded and now hampering the clean-up at Julia Creek.
"Nothing will happen quickly as far as recovery goes," Kidd said. "Don't travel out to this part of the world unless you have to."
The Australian Broadcasting Corporation said the train was travelling from Townsville Port to Phosphate Hill but it was not yet known what the acid was to be used for.
"Four shipments of this type are made a week," it quoted train owner Aurizon as saying in a statement.
Queensland Rail has said it will investigate the cause of the accident.