The head of Uganda's notorious Lord's Resistance Army rebels, Joseph Kony, has arrived at an assembly point in Sudan as agreed in a truce to end his devastating insurgency.
Confirmation of Kony's presence would be a huge boost to what is widely seen as the best chance for an end to a two-decade war in north Uganda which has been one of the world's worst and most neglected conflicts.
"They're all there. (LRA second-in-command) Vincent (Otti) and Joseph (Kony) are there. We are going to discuss the next phase: a comprehensive solution," Martin Ojul, head of an LRA mediating team, said near the Ri-Kwangba assembly point.
Last month, the Ugandan government signed a truce with the LRA, one of Africa's most feared rebel groups, sparking hopes of an end to an uprising that has killed tens of thousands of people and displaced nearly two million.
Led by self-styled mystic Kony, the rebels gained notoriety for their brutal killings of civilians, and for slicing the lips and ears of people they accused of being government informers.
The truce gave the rebels three weeks, until Tuesday, to gather in two agreed locations in Sudan while peace talks continue in the south Sudanese capital Juba.
"There are maybe 4,000 (rebel fighters) there, but I'm just guessing," added Mr Ojul. He said they would discuss issues like resettlement of Ugandans living in refugee camps set up by the government to protect civilians from LRA attacks.
President Yoweri Museveni has drawn criticism for Uganda's policy of herding civilians into squalid refugee camps.
Critics say conditions are miserable and security forces often abuse the people they are meant to be protecting there.