Ugandan military officials are blaming rebels for two attacks in southern Sudan this week that killed 13 people.
Officials Thursday said they suspect fighters from the rebel Lord's Resistance Army ambushed vehicles in the town of Jabuleen, and carried out a separate attack in the town of Magwi.
There were conflicting reports on the number of people killed in each attack, but the reports agree the total death toll was 13.
There was no immediate comment from Ugandan rebel leaders.
Officials in southern Sudan are mediating peace talks aimed at ending the Lord Resistance Army's 20-year insurgency in northern Uganda. Violence in that region has killed tens of thousands of people, and forced more than one million people from their homes.
The talks have been progressing slowly despite a cease-fire the rebels signed with the government in August.