The leader of the Republic of Congo's rebel "Ninja" rebels is due to destroy some of his arms in a ceremony.
The Ninjas, who often wear purple, fought for five years
Frederic Bitsangou, also known as Pastor Ntumi, agreed to disarm after being given a government post.
The man who led a five-year insurgency in the south-eastern region until a deal in 2003 will have responsibility for peace and reconciliation efforts.
His group now wants to transform into a political party. Under the deal, Pastor Ntumi will keep 60 bodyguards.
The BBC's Republic of Congo correspondent, John James, says there has been considerable negotiation over the last month between Pastor Ntumi and President Denis Sassou-Nguesso.
About 250 rebels will be absorbed into the national army and the rest will enter a disarmament and reintegration programme.
The two-day ceremony will take place in Kinkala, the provincial capital of the southern Pool region, to mark the start of the disarmament process.
The Ninjas were founded from a militia group active in the civil wars of the late 1990s, originally loyal to former Prime Minister Bernard Kolelas.
Pool was once known as the "breadbasket of the Congo" but civil war has devastated the area.
Congo is one of sub-Saharan Africa's main oil producers.