Ugandan rebels say they have lost faith in the mediator of the group's peace talks with the Ugandan government.
A spokesman for the rebel Lord's Resistance Army said Thursday that the government of southern Sudan has declared "hostile action" against the group.
On Monday, the president of southern Sudan's semi-autonomous government, Salva Kiir, accused the LRA of terrorizing his region's population. He said everybody with a gun should help the army hunt the rebels down.
The rebel spokesman said Thursday that the LRA has not attacked anyone in southern Sudan.
He also accused southern Sudan of planning to arrest the rebel group's leaders, and hand them over to the International Criminal Court to face war crimes charges.
The peace talks between the rebels and the Ugandan government have stalled in recent months following a ceasefire reached last August.
The talks are aimed at ending the rebels' 20-year uprising in northern Uganda. Fighting in the region has killed tens of thousands of people, and forced more than 1.5 million others into displaced persons' camps.
The ceasefire raised hopes that the talks would be successful. But both sides have accused each other of violations.
The International Criminal Court has arrest warrants for LRA leader Joseph Kony and four of his top aides. LRA fighters are accused of killing, kidnapping and mutilating thousands of civilians during their fight against the Ugandan government.
Some information for this report was provided by Reuters.