The Minister of Information in Northern Liech says the death toll of the fighting between the SPLA and opposition forces in the area has risen to 25.
On Monday, officials said they had recovered 15 bodies, but expressed fears that the number could go up.
The fighting took place in Nhial Dieu County on Monday morning. Information Minister Lam Tungwar says some of the civilians were killed in the crossfire.
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.