The mass graves of up to 1,700 captured Iraqi soldiers killed by the Islamic State group (IS) have been found in the city of Tikrit.
The sites are near the former US Army base, Camp Speicher.
Iraqi forensic teams have begun to excavate 12 graves following the city's recent liberation from IS.
The June 2014 incident is notorious after IS posted videos and pictures of the execution of the mostly Shia soldiers on social media.
Survivors say the militants questioned the victims to identity those who were Shia before killing them.
The exhumations have began just days after Tikrit fell to a combination of the Iraqi army and Shia militias following a month long siege.
DNA testing will be used to identify the bodies once they have been exhumed, as many families have never had confirmation of their relatives' death.