Child soldiers are still being recruited in Myanmar despite the nation's recent political reforms, an advocacy group said Wednesday, as it urged better monitoring of the powerful military.

Myanmar's government agreed in June to a plan with the United Nations to end the use of child soldiers, one of the persistent human rights violations that has brought international criticism of the nation formerly known as Burma.

Child Soldiers International, which carried out three research missions in Myanmar and neighboring Thailand last year, said the army has since freed 42 children and that more could be released.

But the London-based group said that the army, border troops and rebel groups still used children, with the army facing internal pressure to increase its ranks and successful recruiters receiving bonuses or early leave.

"Military officers and informal recruiting agents continue to use intimidation, coercion and physical violence to obtain new recruits, including under-18s," Child Soldiers International said in a report.

Children are also recruited by civilians or police, who find the youngsters on their way to school or in crowded parts of urban areas such as bus and rail stations and markets, the report said.

The group said it was difficult to put an exact number on the number of child soldiers due to the problem's nature. A UN report last year listed 243 complaints of underage recruitment in 2011, but Child Soldiers International said that figure likely represented only a fraction of the cases.

The group voiced hope that the Myanmar government's efforts to broker peace with ethnic rebels would result in agreements on eliminating the use of child soldiers.

The report recommended technical assistance to help Myanmar verify the ages of potential troops and the creation of a central database with information on all forces.

It also called on authorities to ensure punishment for recruiters who violate age standards. A UN task force should visit military sites where children may be present and engage in a dialogue with rebels on the issue, the report said.

One of the most notorious cases of child soldiers involved Johnny and Luther Htoo, who as 12-year-olds led a small group of Christian rebels from the ethnic Karen minority who believed the two brothers were impervious to bullets and landmines.

The boys, who are now in their early 20s, were photographed smoking cigarettes surrounded by followers with guns taller than the boys. They surrendered to Thai forces in 2001.