MANILA, Philippines >> 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, small-scale gold mines under terrifying conditions, a human rights group said Wednesday.

Human Rights Watch’s report said the children work in unstable 25-meter (80-foot) deep pits or underwater along coastal shores or rivers, processing gold with mercury, a toxic metal that can cause irreversible health damage. Those who dive for gold stay underwater for several hours at a time in 10-meter- (30-foot-) deep shafts, receiving air through 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 told the Associated Press that the government is addressing the problem by prosecuting those forcing the children to work, and by providing the children with health, education and livelihood programs.

The Philippines had nearly 5.5 million working children in 2011, according to government statistics, with 3.2 million of them considered child laborers because they worked long hours or in hazardous environments.

"Filipino children are working in absolutely terrifying conditions in small-scale gold mines," said Juliane Kippenberg, associate children’s rights director at Human Rights Watch and author of the report. "The Philippine government prohibits dangerous child labor, but has done very little to enforce the law."

Several boys quoted in the report described the fear they felt when went down a dark, deep shaft for the first time. Dennis, now 14, said he was 13 when he first went under water.

"Sometimes, it feels like your eardrum is going to explode. I stay underwater for one to two hours. (Once) the man above me gave me the warning that something was wrong with the compressor, so I could immediately go up," the report quoted him as saying. "Sometimes if the machine leaks, I smell the fumes. Sometimes I feel dizzy because it’s oil."

"Compressor mining" as it is known locally puts adult and child miners at risk of drowning, decompression sickness and skin infections.

Such small-scale mines can be found more than 30 of the 81 provinces in the Philippines, employing 200,000 to 300,000 from mostly poor, rural communities, the report said. Businessmen finance the operations.

Although the government can designate specific "people’s mining areas," the majority of the small-scale mines operate without a license.

Human Rights Watch urged the government to enforce an order banning mercury use and compressor mining, and said it needs to develop a strategy to stop the use of children in the gold mining industry.