The U.N. war crimes tribunal for Rwanda found former mayor Gregoire Ndahimana guilty of genocide and crimes against humanity Thursday for planning the slaughter of more than 2,000 Tutsi refugees in 1994.

The chamber ... found Ndahimana guilty of genocide and extermination by aiding and abetting as well as by virtue of his command responsibility over communal police in Kivumu, the International Criminal Tribunal for Rwanda said in a statement.

Ndahimana, born on 1952, was sentenced to 15 years in prison after the tribunal dismissed an additional charge of complicity in genocide. He had pleaded not guilty to all charges.

The court said the scale of the operation that led to the destruction of the Nyange church and the murder of thousands of Tutsis reflected a broad coordination by local and religious authorities.

Though this did in no way exonerate the accused, it did, however, suggest that his participation through aiding and abetting may have resulted from duress rather than from extremism or ethnic hatred, the court said.

Nationwide, more than 800,000 Tutsis and moderate Hutus were butchered during a 100-day killing spree.

(Reporting by Fumbuka Ng'wanakilala; Editing by Richard Lough and Jon Hemming)