A sweeping police operation in South Africa has led to the arrest of around 1,000 undocumented miners working in illegal gold tunnels near Barberton, Mpumalanga, with authorities warning that more arrests are likely as others continue to emerge from underground.

Police began the week-long raid on Monday, targeting unauthorized mining activity near the Sheba Mine, close to the borders with Eswatini and Mozambique.

The mine, owned by Barberton Mines, has been under pressure from surrounding communities since it laid off workers earlier this year, citing losses and potential closure.

However, the company now claims the real reason behind its financial difficulties has come to light.

“Earlier this year there was outcry from the community and employees when Barberton Mines retrenched workers as the mine was unprofitable and facing closure. Now we know the reason why!” the company said in a statement.

Barberton Mines added: “Food and supplies have been getting to a thriving illegal mining world underground, which had to be stopped, hence this intervention with the police and mine security. This message needs to be spread and illegal mining will not be tolerated.”

Police spokesperson Donald Mdhluli confirmed the arrests and said the joint operation between police and mine security is ongoing.

“About 1,000 illegal miners who are also illegal immigrants have been arrested,” he said. “As they are coming out, they have been taken.”

Mdhluli also noted that no deaths have been reported so far.

This operation mirrors one conducted last year near Stilfontein, west of Johannesburg, where at least 90 illegal miners died before the mines were permanently shut down in January.

Just like in Stilfontein, the police in Barberton surrounded the mine, cutting off access to food and supplies, forcing miners to surface.