Two men have suffered serious burns at a copper mine in Queensland's northwest.
The contract workers were dismantling scaffolding at the Mount Isa Mines copper smelter on Thursday afternoon when steam blasted from a pressure relief valve next to where they were standing.
They were rushed to hospital with significant injuries, one man in a serious condition and the other stable.
A Resources Safety and Health Queensland investigation is under way.
An inspector travelled to the site and issued a directive to isolate the scene, a spokesperson said.
Mine owner Glencore said the surface operations were suspended for 24 hours from Thursday afternoon while management discussed and reflected on the incident.
"Our immediate focus is on providing support to the injured workers and all those affected," a statement said.
Glencore said it would work with investigators to understand what led to the incident, and reiterated that safe production was the mine's highest priority.
The Australian Workers Union is concerned about how the incident unfolded.
"Tough questions need to be asked about how an incident like this has occurred," secretary Stacey Schinnerl said.
Resources Minister Scott Stewart said he expected a thorough investigation given the responsibility on the sector for worker safety.
"My thoughts are with the workers and their families at what's obviously a very difficult time," he said.