Four miners trapped underground after a tremor caused a rockfall at a mine in northeast South Africa are feared to have been cut off from oxygen, their union said Saturday.
A fifth miner was rescued with serious injuries after the accident at the Tau Lekoa Mine in the town of Orkney on Friday, the National Union of Mineworkers (NUM) said in a statement.
But the rescue team said they lost contact with the four underground miners at around 5:00 am (0300 GMT) on Saturday, sparking fears "they might not be in good health," said NUM president Joseph Montisetse.
"The last person we talked to said: 'We are suffocating please, bring us some oxygen'," he added.
The rescue team "now estimates that it will take three or four days to rescue the four mineworkers because of the massive rocks that continue to fall underground," said the NUM's statement.
Deadly accidents involving miners are common in South Africa, which has the deepest mines in the world.
Last year 81 people died in the country's mines, according to the department of mineral resources.