UNICEF reported at least 89 boys were kidnapped by an armed group in South Sudan on Saturday.

The boys were taken near Malakal in the northern part of the country. The actual number may be higher.

The boys, some as young as 13, were kidnapped while taking their exams in the community of Wau Shilluk in Upper Nile State. The area is home to thousands of people who have been displaced because of the ongoing conflict in the area. Witnesses say the unknown armed soldiers went house to house and took away the boys by force.

Children have been frequently used as soldiers in the ongoing conflict in the area. In the past year, 12,000 children have been recruited and used as soldiers by armed forces and groups in South Sudan, according to the United Nations.

"The recruitment and use of children by armed forces destroys families and communities," said Jonathan Veitch, UNICEF Representative in South Sudan. "Children are exposed to incomprehensible levels of violence, they lose their families and their chance to go to school."

No rebel group has taken responsibility for the abduction. The U.N. and the Human Rights Watch are looking at the South Sudanese government for possibly being behind the kidnapping.

Human Rights Watch reported Monday that South Sudan's government forces and rebels are actively recruiting boys as young as 13 often by force.

The current conflict began in December 2013 when fighting broke out between government troops led by President Salva Kiir and opposition forces led by former vice president Riek Machar.

Veitch said, "The recruitment and use of children in armed forces and groups is a grave violation of international law."

Despite the recent abductions, UNICEF has overseen two sets of demobilization of child soldiers. On Feb. 11. the agency celebrated the release of 300 children from an armed rebel group. Earlier nearly 250 children were released. Some of the child soldiers had been fighting for up to four years, and many had never attended school.