Fifteen people have been killed in clashes between the SPLA and opposition forces Northern Liech State, the information minister has announced.
Lam Tungwar says the fighting took place in Nhial Dieu County on Monday morning.
He told Eye Radio that some of the victims were civilians – women and children.
“This was an unexpected attack, an act that we strongly condemn. It is not something unacceptable,” Mr Tungwar stated.
Eye Radio was unable to contact the opposition leaders for comment.
International and regional leaders have called for an end to the conflict in South Sudan.
Over a million South Sudanese refugees have fled to the neighboring countries, with Uganda alone hosting 1 million.
More than 417,000 South Sudanese refugees are sheltering in Sudan since conflict broke out in December 2013, according to the UN Refugee Agency.