Reports from Brazzaville say forces loyal to President Denis Sassou Nguesso have killed several dozen rebel militiamen in fighting close to the southwestern outskirts of the capital.
A number of government troops are also said to have died in the operation aimed at flushing the self-styled Ninja militiamen out of the area.
The Ninjas supported the government ousted by President Sassou Nguesso in 1997.
From the newsroom of the BBC World Service