United Nations investigators tracking one of the most notorious killers in the Rwandan genocide believe he is hiding in Zimbabwe and are launching a new effort to convince authorities in Harare to allow the 60-year-old fugitive to face trial. Protais Mpiranya, the former commander of the presidential guard of the Rwandan army, has been on the run for 27 years charged with war crimes, genocide and crimes against humanity. The ex-soldier is top of a list of remaining fugitives indicted by an international tribunal into the 1994 killings, which left 800,000 people dead in Rwanda, mostly from the Tutsi ethnic minority but also some Hutus. Mpiranya had been second on the wanted list before the arrest of Félicien Kabuga, a former businessman alleged to have helped finance the genocide, on the outskirts of Paris in May. The US war crimes reward programme has offered a $5m reward for information leading to Mpiranya’s arrest.