Critics of Rwanda's government say the killing in South Africa this month of a prominent Rwandan dissident is another sign of an increasingly violent power struggle among the country's Tutsi elite who have held power since 1994.

Former Rwandan spymaster Patrick Karegeya, whose death has been blamed on Rwanda's government, belonged to a generation of Tutsi army officers who fought alongside President Paul Kagame in the Uganda-backed rebellion whose victory stopped the 1994 genocide.

That network of Kagame's war-time allies has been dwindling as some defect following disagreements with Kagame, who warns that those who "betrayed the nation cannot escape the consequences."

Charles Rwomushana, an independent analyst who previously worked for Uganda's domestic intelligence service, said Kagame wants to "build a new layer" of army officers whose loyalty is unquestioned.