Rwanda's President Paul Kagame and his wife, Janet Kagame, light a flame that will burn for 100 days, the length of time it took government soldiers and "Hutu power" militiamen to carry out their plan to wipe out the minority Tutsis in 1994, at the Gizosi Genocide Memorial in Kigalia on Monday. Photo: AFP

Rwanda on Monday held solemn commemorations to mark the 20th anniversary of the genocide, with many survivors overcome with the emotion of reliving the trauma of the massacres that left nearly a million dead.

The events also bore reminders of festering anger as a major diplomatic row broke out over renewed allegations of French complicity in the genocide.

Paris had cancelled a ministerial visit in response to the accusations by Rwandan President Paul Kagame, and on Monday the French ambassador was barred from attending commemoration ceremonies.

Official mourning, which began three months ago with a flame of remembrance touring towns and villages across the small central African nation, culminated on Monday when the torch arrived at the national genocide memorial, where the remains of a quarter of a million people are stored in vast concrete tombs.

Kagame lit a flame that will burn for 100 days, the length of time it took government soldiers and "Hutu power" militiamen to carry out their plan to massacre the minority Tutsi.

The well-planned and viciously executed genocide began late on April 6, 1994, shortly after Hutu president Juvenal Habyarimana was killed when his plane was shot down over Kigali. Roadblocks were set up, with Tutsi men, women and children of all ages butchered with machetes, guns and grenades.

An estimated 800,000 people, mostly Tutsis and some moderate Hutus, died in the killings.

Wreathes were also laid, before ceremonies in Kigali's football stadium where UN Secretary General Ban Ki-moon, several African heads of state and top diplomats from Europe and the US were gathered.

At the national stadium, survivors of the genocide recounted their memories of the killings and of their survival. Several people were overcome with trauma, screaming and crying uncontrollably with medical staff helping to carry them out and to provide counseling.

AFP