A global coalition to stop the use of child soldiers says there are up to 7,000 child fighters in Burma.
In a new report, the world body says nearly every armed group in the East Asian country has used troops between the ages of 11 and 18.
It says Burmese children are forcibly recruited, brutally treated during training, and coerced into taking part in combat.
The report says Burma's government maintains a network of camps (called the Ye Nyunt or "new leaf" system) where children are held and trained until they are big enough to join the armed forces.