A top suspect accused of orchestrating the killings of thousands during Rwanda's 1994 genocide has pleaded not guilty to war crimes charges.

Idelphonse Nizeyimana entered his plea Wednesday at the International Criminal Tribunal for Rwanda.

Nizeyimana is accused of ordering the killing of children, hospital patients, priests and even an elderly and revered African queen.

He had been on the run for 15 years with a $5 million bounty on his head when he was captured in Uganda earlier this month.

More than 500,000 members of the Tutsi ethnic minority and moderates from the Hutu majority were slaughtered during the 100-day Rwandan genocide in 1994.