Burundi's ex-president Pierre Buyoya, currently the African Union's special envoy to Mali, has been sentenced to life in prison in absentia over the assassination of his successor in 1993, according to the court ruling seen by AFP Tuesday. Buyoya was convicted for "an attack against the head of state" over his role in the killing of the first democratically elected president, Melchior Ndadaye, during a coup d'etat which plunged the country into civil war. str-fb/gd