The U.N. tribunal for Rwanda has sentenced two former politicians to life in prison for their roles in the country's 1994 genocide.

Mathieu Ngirumpatse and Edouard Karemera were president and vice president of Rwanda's then-ruling MRND party at the time of the genocide.

The tribunal found them guilty on charges of genocide, war crimes, and crimes against humanity for failing to stop or punish crimes committed by the party's youth militia, the Interahamwe. The crimes included rape and murder.

A third man indicted with the two politicians, Joseph Nzirorera, died during the trial.

Rwandan Hutu extremists killed an estimated 800,000 ethnic Tutsis and Hutu moderates during the killing spree between April and July 1994.

The Tanzania-based International Criminal Tribunal for Rwanda was set up to try those most responsible for the crimes.