As Rwanda marks 20 years since its genocide, we report on the Hutus who fled to neighbouring Democratic Republic of Congo after the Tutsis took power. About two million people crossed the border, including militiamen who took part in the slaughter, and they set up the FDLR - the Democratic Forces for the Liberation of Rwanda - the self-proclaimed defenders of Hutu refugees. France 24's correspondents Léa-Lisa Westerhoff and Mehdi Meddeb have been to meet them.