The European Union has imposed sanctions on two South Sudanese military leaders for breaking ceasefire agreements.
It accused rebel leader Peter Gadet and army commander Santino Deng of links to atrocities over the past six months.
Both men are subject to a travel ban and asset freeze.
Thousands of people have died in the fighting that erupted between different factions of South Sudan’s governing party.
More than a million people have fled their homes since a political dispute between President Salva Kiir and his former deputy, Riek Machar, escalated into ethnic violence.
Gen Gadet defected from the South Sudanese army and joined Mr Machar’s rebels shortly after fighting broke out in December 2013.
Both men are ethnic Nuers.
He is accused of leading the attack on the oil hub of Bentiu in April, in which some 200 civilians were killed, despite a ceasefire agreement.
(Source BBC News)