The Acting Minister of Information in Upper Nile State says fighting resumed in Malakal town this afternoon between forces of General Johnson Olony and those loyal to Governor Simon Kun Puoch.
Gatluak Liphoth says some civilians have been caught up in cross fire, but he did not provide the casualty figure.
SPLA spokesman Col Philip Aguer has confirmed the fighting but said there were no details.
The United Nations says more than 1,500 people fled to their IDP camps in the area.