A UN report calls for the release of 900 civilians and children South Sudan People Defence and Opposition forces abducted during their war.
The report points out that the abducted young men and boys were forced to be fighters or used as porters.
UN High Commissioner for Human Rights Michelle Bachelet says most of the abducted civilians are still being held captive.
She urges the SPLA-IO to immediately release them, first and foremost the children.
Bachelet also urges the government to hold the perpetrators of the abuses and violations to account as part of the revitalised peace process.
Head of UNMISS David Shearer expresses disappointment that the violence took place while warring parties have signed a new peace agreement.
He pledges that UNMISS will be closely monitoring any potential violations and abuses of the newly signed peace agreement.
The report shows attacks and abuses of international laws carried out by opposition forces on at least 28 villages, a settlement of internally displaced persons and a refugee camp, in Gbudue and Tombura.
UNMISS Human Rights Division says it has identified three opposition commanders who allegedly had effective command and control of the forces committing these abuses, which may amount to war crimes.
The agency states that forces also carried out military operations that are serious violations including unlawful killings and destruction of civilian property around Nagero in May 2018.
The report calls for accountability and reinforcement of existing recovery and resilience programmes to re-establish access to basic services.