Rescue teams in South Africa have stepped up efforts to pull out survivors and the corpses of illegal miners trapped underground for about two months, following one of the most extraordinary tragedies to hit the industry.

South African officials have arrested more than 100 miners who had been trapped in an illegal gold mine and will detain hundreds more still stuck underground, the country’s mining minister said, despite a judge’s warning that the ordeal risks turning into “the darkest point” in the country’s history following dozens of deaths.

The authorities had at one point limited the miners’ access to food, water and other supplies in a blockade that drew criticism from human rights groups.