Attacks by the forces of rebel leader George Athor killed 197 civilians, according to the Sudan People’s Liberation Movement, which called it a massacre.
Troops loyal to Athor attacked SPLA soldiers on 9 February in spite of a ceasefire between Athor and the southern army, which was signed last month.
There have been no new clashes since fighting ended last Thursday, but authorities have only this week become aware of many of the civilians who died.
The attacks came days after the formal confirmation of the results of the 9-15 January referendum on southern independence, in which almost 99 per cent of southerners voted to secede from the north.
Athor accused the SPLA of starting the attacks, on the the independent Sudan Radio Service last week.
He launched his rebellion last year after claiming he was cheated in an election for the governorship of Jonglei state.