Almost 170 million young people are trapped in child labor, deprived of education and face a life without decent jobs, the International Labour Organization said on Wednesday.

From India's brick kilns to the cotton fields of Uzbekistan and Bolivia's sugar plantations, child laborers are more likely to have to settle later in life for unpaid work for their families or low-paying jobs, the organization said in its annual World Report on Child Labour.

"Children who drop out of school and join the labor force early are more disadvantaged later in life because of a lack of education and basic skills," said Patrick Quinn, a senior adviser.

Despite an overall decline in child laborers by one-third since 2000, some 5 million children make up a quarter of the world's modern-day slaves, the organization said.

The Asia-Pacific region has the largest number of child laborers, with almost 78 million, or 9.3 percent, while sub-Saharan Africa has the highest rate with 59 million, or more than 21 percent.

Many of them are working under conditions that deprive them of a nurturing and protective environment, and expose them to stress and trauma, the group said.

More than half of all child laborers, 85 million, put their health at risk by working in hazardous jobs, such as mining and construction, said the report, released ahead World Day Against Child Labour on Friday.