The Sudan Doctors Network, a medical group tracking the war, said the death toll could rise as rescuers search for people buried under the rubble.
A local administration official told AP that 82 bodies had been recovered. The official said dozens of people remained missing.
The collapse began on Sunday in one mine shaft before spreading to other interconnected shafts.
Only one privately owned forklift is available for rescue efforts, making the search difficult.
Survivor Khairal-Sayed Gabara described the collapse as "massive". He said machinery needed to remove the soil and rubble was not available.
"We do not have the machinery to lift dirt and stones and search for survivors at depths of more than 30 metres (98 feet)," he was quoted as saying. "There were dozens of people working in the mine."
Another survivor, Al-Amin Suliman, said 60 bodies had been recovered by Wednesday morning.
The Kordofan Observatory, a monitoring group, said at least 70 miners were killed or missing at the site. The mine stretches for more than 1 kilometre across fragile, sandy soil.
The Sudan Doctors Network said the mine was an informal site employing unregulated workers and lacked basic safety and protective measures.
Sudan is a major gold producer. Deadly mine collapses are not uncommon in the country, where thousands of informal and small-scale mines operate with limited safety measures.
A mine collapse in 2023 killed 14 miners, while another in 2021 killed 38.
The al-Zara mine is among thousands of small-scale and informal gold mines spread across Sudan.