Armed groups in South Sudan released 145 children on Tuesday, the U.N. children's agency (UNICEF) said, calling on warring parties to stop recruiting child soldiers as the world's youngest nation teeters on the brink of renewed civil war.

 

The children were released by the rebel SPLA-In-Opposition, led by former Vice-President Riek Machar, and the Cobra Faction, which signed a peace deal with the government in 2014.

 

"Our priority is to get them into school and to provide services to communities so the children are able to see a more promising future," UNICEF's South Sudan representative, Mahimbo Mdoe, said in a statement.

 

"With the ongoing fighting across the country, UNICEF continues to receive reports about the recruitment of children in Unity, Jonglei and other states."

 

The children were released in Jonglei State's Pibor area, to the northeast of the capital, Juba.

 

Oil-rich South Sudan descended into civil war in December 2013 when a row between President Salva Kiir and his sacked deputy, Riek Machar, ended with fighting that often occurred along ethnic fault lines.

 

A peace deal was signed in 2015 but violations have been frequent, and heavy fighting broke out again in July.

 

Machar fled the country and is seeking medical treatment in South Africa.

 

He has urged his forces to reorganize for armed resistance to Kiir's government.

 

Rising hate speech and incitement to violence against certain ethnic groups which could result in mass atrocities if the government does not act, the United Nations said on Tuesday.

 

Some 16,000 children serve in armed forces in South Sudan, with an estimated 800 newly recruited in 2016, UNICEF said.

 

Tuesday's release is the largest so far this year, following the demobilization of 1,775 children in 2015, mostly by the Cobra Faction.

 

UNICEF warned in August of an imminent spike in forced recruitment of child soldiers.

 

Forces attacking villages often grab children and force them, at gunpoint, to fight, rights groups say.

 

Others join to save themselves from being beaten or killed and to protect their communities.

 

Half of children in South Sudan do not go to school - the highest proportion in the world, UNICEF said.

 

After being disarmed and provided with civilian clothes, the children undergo medical screening and take part in a reintegration program which includes psychosocial support.

 

Once their families are traced, they receive three months of food aid and livestock, UNICEF said.