A man waves Armenian and Georgian flags at a memorial to Armenians killed by the Ottoman Turks, during marking the centenary of the mass killings, in Yerevan, Armenia, Friday, April 24, 2015. Armenians on Friday mark the centenary of what historians estimate to be the slaughter of up to 1.5 million Armenians by Ottoman Turks, an event widely viewed by scholars as genocide. Turkey, however, denies the deaths constituted genocide and says the death toll has been inflated.