A bus carrying wounded service members of Ukrainian forces from the besieged Azovstal steel mill in Mariupol drives under escort of the pro-Russian military in the course of Ukraine-Russia conflict upon arrival in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko TPX IMAGES OF THE DAY 

A service member of pro-Russian troops stands guard next to a combat vehicle, with the symbol "Z" seen on its side, before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko TPX IMAGES OF THE DAY 

A wounded service member of Ukrainian forces from the besieged Azovstal steel mill in Mariupol is transported on a stretcher out of a bus, which arrived under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko TPX IMAGES OF THE DAY 

Service members of pro-Russian troops wait before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Russian service members stand guard on a road during sunset before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Buses carrying service members of Ukrainian forces from the besieged Azovstal steel mill drive away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A Russian service member waits atop an armoured vehicle before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A view shows a bus carrying service members of Ukrainian forces from the besieged Azovstal steel mill in Mariupol, which arrived under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops stands guard before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops stand guard on a road before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops wait atop an armoured personnel carrier before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops stand guard on a road before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A bus carrying service members of Ukrainian forces from the besieged Azovstal steel mill drives away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops waits before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A view shows buses carrying service members of Ukrainian forces from the besieged Azovstal steel mill in Mariupol, which arrived under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A convoy of pro-Russian troops is seen before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A wounded service member of Ukrainian forces from the besieged Azovstal steel mill in Mariupol looks out of a bus, which arrived under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops stand guard on a road before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A convoy of pro-Russian troops, which escorts buses with service members of Ukrainian forces from the besieged Azovstal steel mill, drives away in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A bus carrying service members of Ukrainian forces from the besieged Azovstal steel mill drives away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A wounded service member of Ukrainian forces from the besieged Azovstal steel mill in Mariupol is transported on a stretcher out of a bus, which arrived under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A serviceman of pro-Russian troops stands inside a bus carrying wounded members of Ukrainian armed forces from the besieged Azovstal steel mill in Mariupol in the course of Ukraine-Russia conflict in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops stand guard on a road before the expected evacuation of wounded Ukrainian soldiers from the besieged Azovstal steel mill in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A bus carrying wounded service members of Ukrainian forces from the besieged Azovstal steel mill in Mariupol drives under escort of the pro-Russian military in the course of Ukraine-Russia conflict upon arrival in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A bus carrying wounded service members of Ukrainian forces from the besieged Azovstal steel mill in Mariupol drives under escort of the pro-Russian military in the course of Ukraine-Russia conflict upon arrival in Novoazovsk, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A bus carrying service members of Ukrainian forces from the besieged Azovstal steel mill drives away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 16, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops rides an armoured personnel carrier escorting buses with service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works are seen inside a bus driving away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Buses carrying service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works drive away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works are seen inside a bus driving away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Buses carrying service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works drive away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Buses carrying service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works drive away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Service members of Ukrainian forces who have surrendered after weeks holed up at Azovstal steel works are seen inside a bus driving away under escort of the pro-Russian military in the course of Ukraine-Russia conflict in Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops walk along a street in the southern port city of Mariupol, Ukraine May 17, 2022. REUTERS/Alexander Ermochenko