The party of jailed Rwandan opposition leader Victoire Ingabire says it will continue fighting for the "total liberation" of Rwanda after the country's highest court on Friday upheld her conviction and raised her jail term from eight to 15 years.

Ingabire's FDU-Inkingi party said in a statement received Saturday that the verdict was "devastating" and that Rwanda is now under a "yoke of dictatorship."

Ingabire had appealed her conviction in October 2012 over offenses including trivializing the history of the 1994 genocide, and the raised jail term appeared to surprise her supporters.

Human Rights Watch has said some charges against her were politically motivated.

Ingabire was arrested not long after returning to Rwanda from exile in 2010 to contest the country's presidency.