(Reuters) - The U.N. war crimes tribunal for Rwanda on Friday acquitted two former Rwandan ministers of genocide charges, making them among the most high profile officials to be found not guilty of playing key roles in the 1994 slaughter of about 800,000 people.

The International Criminal Tribunal for Rwanda ordered the immediate release of former Health Minister Casimir Bizimungu and Jerome-Clement Bicamumpaka, who was foreign affairs minister at the time of the mass killings.

The Trial Chamber convicted two other former ministers, Justin Mugenzi and Prosper Mugiraneza, of conspiracy to commit genocide and direct and public incitement to commit genocide.

Both were sentenced to 30 years in prison.