According to the United Nations’ children’s agency, there has been a spike in the forced recruitment of child soldiers in South Sudan, as the country titters on the brink of civil war.

Despite a peace deal constructed in August 2015, fierce fighting broke out in the capital Juba last month, killing hundreds of people.

On Friday, the UNICEF announced that at least 650 children have joined armed groups within South Sudan during this year alone. Around 16,000 child soldiers have been recruited since the civil war broke out in December 2013.

According to an internal United Nations document obtained by The Associated Press, a senior politician, appointed by President Salva Kiir, conducted the recruitment of an entire village of boys using coercion.

The U.N. document indicates that the recruitment of children took place shortly after the U.N. Security Council approved sending an additional 4,000 peacekeepers to the African country in July, to protect civilians after fighting resumed in Juba.

Armed groups in South Sudan often force children to join their ranks by threatening to confiscate their family’s cattle, a key source of wealth and status in Sudan’s pastoral society. Other times, the boys are forced to join at gunpoint, or with the threats of beatings.

“At this precarious stage in South Sudan’s short history, UNICEF fears that a further spike in child recruitment could be imminent,” UNICEF’s deputy executive director Justin Forsyth said in a statement after visiting South Sudan. “The dream we all shared for the children of this young country has become a nightmare.”

Child soldiers, by definition, are soldiers that are under the age of 18, and the International Criminal Court considers the recruitment of those under 15 to be a war crime.

“They believe they can easily control and manipulate young minds,” Forsyth said. The children then “can commit atrocities, and they will do what they are told.”

Perhaps the surest and cruelest way to rob one’s youth is to put him on the front line of his country’s war, with a gun in his hands. And as the civil war rages on, so do its casualties.