South African President Cyril Ramaphosa is facing calls to order a national inquiry into a police operation that was meant to combat illegal mining but ended up leaving 87 miners to die underground as authorities attempted to force them to surrender during a monthslong standoff.

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.

The South African government has launched a rescue operation at an abandoned gold mine in the country’s North West province, where at least 109 men have died, a group representing the miners said, after local authorities cut off vital supplies in a dramatic bid to crack down on the country’s illegal mining trade.