Members of Ukrainian Emergency Service, police and experts work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Members of Ukrainian Emergency Service, police and experts work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Crosses with numbers are seen at a place of mass burial, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Experts carry a body as they work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich TPX IMAGES OF THE DAY 

Experts carry a body as they work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Experts carry a body as they work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Experts carry a body as they work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

A cross with number is seen as members of Ukrainian Emergency Service work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Experts work at a place of mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Members of Ukrainian Emergency Service, police and experts work at a mass burial site during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Police work at a mass burial site during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Members of Ukrainian Emergency Service rest as they work at a mass burial site during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Ukrainian servicemen guard a mass grave site during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Crosses with numbers are seen at a mass grave site, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Ukrainian servicemen guard the site of a mass burial during an exhumation, as Russia's attack on Ukraine continues, in the town of Izium, recently liberated by Ukrainian Armed Forces, in Kharkiv region, Ukraine September 16, 2022. REUTERS/Gleb Garanich 

Signal tape is seen over a grave of an unidentified Ukrainian soldier at an improvised cemetery in the town of Izium, recently recently liberated by the Ukrainian Armed Forces during a counteroffensive operation, amid Russia's attack on Ukraine, in Kharkiv region, Ukraine September 15, 2022. REUTERS/Oleksandr Khomenko 

Crosses with numbers are seen at an improvised cemetery of unidentified civilians and Ukrainian soldiers in the town of Izium, recently recently liberated by the Ukrainian Armed Forces during a counteroffensive operation, amid Russia's attack on Ukraine, in Kharkiv region, Ukraine September 15, 2022. REUTERS/Oleksandr Khomenko 

A Ukrainian serviceman installs a signal tape at a site on an improvised cemetery of unidentified civilians and Ukrainian soldiers in the town of Izium, recently recently liberated by the Ukrainian Armed Forces during a counteroffensive operation, amid Russia's attack on Ukraine, in Kharkiv region, Ukraine September 15, 2022. REUTERS/Oleksandr Khomenko 

A Ukrainian serviceman walks among graves of mostly unidentified civilians and Ukrainian soldiers at an improvised cemetery in the town of Izium, recently recently liberated by the Ukrainian Armed Forces during a counteroffensive operation, amid Russia's attack on Ukraine, in Kharkiv region, Ukraine September 15, 2022. REUTERS/Oleksandr Khomenko 

A Ukrainian serviceman uses a metal detector to inspect a mass grave at a site on an improvised cemetery of civilians and Ukrainian soldiers in the town of Izium, recently recently liberated by the Ukrainian Armed Forces during a counteroffensive operation, amid Russia's attack on Ukraine, in Kharkiv region, Ukraine September 15, 2022. REUTERS/Oleksandr Khomenko