The incident took place over the weekend, leaving rescuers scrambling for survivors.
Five people survived the incident are were being treated at a nearby hospital.
Rescue efforts have continued on the site on Monday as more people are believed to the trapped beneath the mine located in Tanzania’s Morogoro region.
The mine was operating without a license, Tanzanian authorities say.
The site had witnessed some small-scale mining activities since the area was discovered as holding a large gold reserve a few years ago.