Police say the death toll in a monthslong standoff between authorities and miners trapped while working illegally underground at an abandoned gold mine in South Africa has risen to at least 87.

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.

At least 78 people have died after authorities imposed a blockade on an illegal gold mine here, part of a monthslong standoff between prospectors and a government determined to force them to surface—often by cutting off their food and water.