Colombian rescuers on Thursday hunted for more than a dozen people feared trapped beneath debris left by in the collapse of an illegal gold mine that killed at least three people, officials said.

Cauca province Gov. Temistocles Ortega said the collapse occurred shortly before midnight in a rural area near Santander de Quilichao, about 190 miles (315 kilometers) southwest of Bogota, the capital.

By mid-afternoon, rescue workers had recovered the bodies of three dead and three injured, and he said they were searching for about 15 people still missing, according to the municipal police chief, Felipe Chacon.

The governor said illegal miners use machinery to open huge holes to extract gold, and one of the walls of a hole fell in.

Police, troops, civil defense and the Red Cross were aiding in rescue efforts.