A French appeals court has rejected Rwanda's request to extradite the widow of the late Rwandan President Juvenal Habyarimana.

Rwandan prosecutors say former first lady Agathe Habyarimana played a key role in the country's 1994 genocide.

French authorities arrested her last year, after Rwanda issued a warrant charging her with genocide and crimes against humanity.

Prosecutors have accused the widow of helping to mastermind a massive killing spree after her husband's assassination when his plane was shot down near Rwanda's capital on April 6, 1994.

The event is widely considered the trigger for the Rwandan genocide, in which Hutu extremists killed about 800,000 ethnic Tutsis and moderate Hutus during a span of 100 days.