From Rob McKee in Juba:
Fighting is reported near Malakal at this time.
Its not known whether the fighting has reached the center of town but militia were in control of areas south of the city up until today, while government forces controlled the northern sector.
Earlier today UN flights to Malakal from Juba were cancelled following reports of shooting between the airport and the UN base.
Malakal saw fierce fighting several weeks ago after the SPLA division split along ethnic lines.
Other neighbouring counties in Upper Nile State, of which Malakal is the capital city, have also see a surge of violence in the past few weeks.
Upper Nile State is the major producing oil state in South Sudan.
