Rwanda 20 years since genocide: a warning: this video contains distressing images

In 1994, 900 thousand people were massacred in Rwanda in the worst genocide since the Holocaust. The killers used machetes and nail-studded clubs.

Yesterday the country has begun a week of mourning to mark the 20th anniversary. At a ceremony in Kigali, Ban Ki-Moon told Rwandans the UN is still ashamed over its failure to prevent the killings. Our International Editor Lindsey Hilsum - who was in Kigali when the genocide started - now reports. And a warning: her report does contain distressing images.