The UN human rights chief said up to 50,000 civilians in South Sudan's Upper Nile region are at imminent risk of human rights violations as government troops close in.

Zeid Ra'ad al-Hussein said Thursday that civilians in Aburoc town have nowhere to go, adding that many recently fled a military attack on nearby Kodok town.

“There are concerns that rebels have positioned themselves in close proximity to civilian areas, placing civilians clearly in danger in the event of an attack by the army and affiliated forces,” the UN official said.

He urged the government of South Sudan to halt any further military offensives towards Aburoc on the west bank of the River Nile in the Upper Nile region, where between 35,000 and 50,000 people, most of whom arrived in recent weeks are currently sheltering.

“Civilians in Aburoc are at serious and imminent risk of gross human rights violations, inter-ethnic violence and re-displacement," Zeid said.

The UN rights chief pointed out that a large number of people who walked long distance after fleeing from Tonga and Kodok areas, amid reports that many died the long the way due to dehydration and exhaustion.

“The rest ended up in Aburoc where, weary and frightened, they face grave violence and shortages of food, water and healthcare,” said Zeid.

Zeid pointed out that military commanders on both sides show little regard for protecting civilians.

He urged the government to adhere to the pledges made by President Salva Kiir on 25 March, when he committed to declare a unilateral ceasefire, and to work towards political engagement to bring the conflict to an end.

Zeid also called on all parties to the conflict to comply with international humanitarian law, including taking all feasible precautions to prevent civilian casualties.

“The civilians in Aboruc have nowhere left to go, with the SPLA closing in from the south and options to flee northwards severely limited and fraught with danger,” Zeid said.

“I urge the SPLM/A-IO to ensure that areas containing large numbers of civilians, including Aburoc, are demilitarized and that measures are taken to ensure the protection of civilians under their control,” he added.

The civilians in Aburoc are mostly of Shilluk ethnicity.