Governments are trying to stop human trafficking but their programs are falling far short. Organized crime networks, whose operations thrive on corruption, often manage the business.
Poverty is behind the problem. Traffickers promise children work, then press them into prostitution or forced labor.
The United Nations' International Labor Organization, or I-L-O, two years ago estimated the number of exploited child laborers in Asia's factories or farms at more than 100 million.
The I-L-O defines child labor as exploitative when it harms education or health, and so does not include children who work as part of their families' economic activities while in school.
Frans Roselaers from the I-L-O's child protection program says governments along the Mekong River are now cooperating on measures to stop child trafficking.
For example, Thailand last year signed an agreement with neighboring Cambodia to allow the repatriation of Cambodian children found working illegally in Thailand.
Carmen Madrinan, executive director of the Bangkok rights group ECPAT, says regional cooperation has not happened fast enough to stop what has become a booming business. She says,
"We have had an exponential rise in trafficking of children in the region. This is a cross-border problem, and it's an international problem."
A recent ECPAT report estimates that up to 250- thousand women and children are trafficked in Southeast Asia each year.
Most come from Burma, China's southern Yunnan Province and Laos, while Thailand acts as both a transit and destination country.
Thailand has as many as two hundred thousand child laborers, and in recent years, the government has enacted tougher legislation to stop child trafficking. It also has promised to set up regional centers for tougher enforcement of the laws.
Ms. Madrinan of ECPAT says better laws and enforcement have not stopped child trafficking because once regulations are strengthened in one country, traffickers move on to countries or regions where enforcement is weak.
Northern Thailand, which shares borders with Laos and Burma, is a good example. Child advocates in the area say the government has promised funding to strengthen regional child welfare groups, but the problem is getting worse.
Sompop Jantraka, a spokesman for the child protection group Daughters Education Program, says his organization has been waiting for more than a year for money promised by the government. He adds,
"It has been almost one-and-a-half years already but has not seen anything improve yet. We are too slow, we are too late and we are too worried…" Mr. Sompop says trafficking in northern Thailand is well organized and largely under the control of the local crime groups, who corrupt police and other officials.