The United Nations has called for an investigation into the deaths of 87 people whose bodies have been found in a mass grave in Sudan’s Darfur region. The UN human rights office says they have credible evidence of Sudan’s Rapid Support Forces (RSF) being involved in the killings. The RSF is currently fighting the country’s armed forces and violence has been escalating. The World’s Africa correspondent Halima Gikandi has been finding out more.