A human rights group says the Philippine government has failed to protect thousands of children, some as young as 9 years old, who risk their lives by working in illegal gold mines under terrifying conditions.

Human Rights Watch's report released Wednesday said children work in unstable 25-meter (80-foot) deep pits or underwater along coastal shores or rivers, processing gold with mercury, a toxic metal. Those who dive for gold stay underwater for hours in 10-meter- (30-foot-) deep shafts, receiving air from a tube attached to an air compressor.

The New York-based group says it interviewed 135 people, including 65 child miners from 9 to 17 years of age, in eastern Camarines Norte and Masbate provinces in 2014 and 2015.

Labor Secretary Rosalinda Baldoz says the government is addressing the problem.