At least 14 suspected illegal miners were killed and eight injured when a mine dump collapsed in South Africa’s North West province on Monday night, police said.

Search and rescue teams with sniffer dogs and specialised equipment are scouring the rubble for an unknown number of people who may still be trapped.

The collapse happened around 9 p.m. on Monday at the Nkaneng dumping site in Bojanala Sub-District 2, near Rustenburg, according to North West provincial police commissioner Lieutenant General Arthur Adams.

The miners were digging for platinum group metals at a disused dump on a private company’s site when the walls of an excavated area caved in, trapping them underground.

“SAPS is deploying specialised resources like our search and rescue dogs and specialised equipment to detect if there are no more people that are further trapped under the rubble,” Adams said. “We cannot just move along and assume that it is only 14 that passed away.

“We still owe it to the families that we have to wrap up and conclusively then come to understanding that there is nobody else that is still trapped.”

Police said a nearby security guard was alerted by an illegal miner who reported the incident before disappearing. Officers called to the scene recovered 14 bodies.

Eight injured miners were taken to hospital. All are undocumented Lesotho nationals. Three have been discharged and taken into police custody for allegedly contravening the Immigration Act.

The remaining five remain hospitalised under police guard. The nationalities of those killed have not yet been confirmed.

“An inquest investigation has also been opened to establish the circumstances surrounding the incident,” Adams said.

The site is managed by Sustenza Trading from Mooinooi, which holds a permit for platinum group metals exploration, according to police.

Illegal mining has plagued South Africa for decades, ranging from small-scale theft to operations run by organised criminal networks.

Undocumented miners often enter abandoned commercial mines to extract remaining deposits, sometimes under the control of violent gangs. The activity costs the government and mining industry hundreds of millions of dollars annually in lost sales, taxes and royalties.

In February, President Cyril Ramaphosa authorised the deployment of the South African National Defense Force to assist police in combating illegal mining.

Adams said search operations would continue until authorities can confirm no one else remains trapped.