Rwanda and Congo on Friday announced the arrest of rebel leader Laurent Nkunda in Rwandan territory.
General Nkunda has led a Tutsi rebellion in eastern Congo since 2004. He was detained late on Thursday and the Congo government said it would seek his extradition. He is wanted for war crimes.
Rwanda sent more than 3500 troops into Congo this week, marking unprecedented cooperation between the Great Lakes neighbours after years of suspicion and hostility.
Wars, rebellions and ethnic violence since 1998 have killed more than 5 million people in the former Belgian colony.
The United Nations has a peacekeeping force of 17,000 troops and police in Congo.