A rights group says government and opposition forces in South Sudan continue to recruit child soldiers, despite promises they would stop. Human Rights Watch says some of the boys are as young as 13.
Government forces are in control in Malakal in Upper Nile State.
"What our research has shown is that over the Christmas period and in early January especially, there was a spike in recruitment in Malakal. And that included people who were underage children, including kids as young as 13. We spoke to many mothers whose kids had willingly gone off to join these forces. Other kids who had been taken by force from Malakal town, but in several cases from right outside of the U.N. base," she said.
Wheeler said about 20,000 civilians are still seeking refuge at that base.
The Human Rights Watch researcher said that she spoke to a number of former child soldiers who were recruited to fight last year.
Wheeler said child soldier recruitment is widespread in the country.
South Sudan's 2008 Child Act forbids the use of child soldiers. It sets a minimum age of 18 for either conscription or for voluntarily joining armed groups.
"This conflict has really taken us back -- many, many steps backwards in that process. The SPLA established a whole mechanism with offices whose job was to make sure that there were no children in any of the barracks. And actually South Sudan, although it did still have child soldiers, had made quite considerable steps towards having a child-free army," she said.
Another problem is that many schools have been taken over by armed groups. Wheeler says that's despite both sides agreeing last year that they would not do so, as well as recommitting themselves to not using child soldiers.
The South Sudanese government called the Human Rights report nonsense, saying it does not recruit child soldiers. It said HRW is using old reports and that its army has many recruits and does not need children.
The opposition said since it signed an agreement last May not to recruit child soldiers it has abided by that agreement.