Smoke rises above a plant of Azovstal Iron and Steel Works company during Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 20, 2022. REUTERS/Alexander Ermochenko 

A view shows a plant of Azovstal Iron and Steel Works company during Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 19, 2022. REUTERS/Alexander Ermochenko 

A view shows a plant of Azovstal Iron and Steel Works company behind buildings damaged in the course of Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 19, 2022. REUTERS/Alexander Ermochenko 

A view shows a plant of Azovstal Iron and Steel Works company during Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 19, 2022. REUTERS/Alexander Ermochenko 

Smoke rises above a plant of Azovstal Iron and Steel Works company and buildings damaged in the course of Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 18, 2022. REUTERS/Alexander Ermochenko 

A view through smoke shows a plant of Azovstal Iron and Steel Works company during Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 18, 2022. REUTERS/Alexander Ermochenko 

Smoke rises above a plant of Azovstal Iron and Steel Works company and buildings damaged in the course of Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine April 18, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops ride an armoured vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops ride an armoured vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops ride an armoured vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops rides a moped during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops walk in the street during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops load rocket-propelled grenades into an infantry combat vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops loads rocket-propelled grenades into an infantry combat vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops load rocket-propelled grenades into infantry combat vehicles during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops load rocket-propelled grenades into an infantry combat vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops loads rocket-propelled grenades into an infantry combat vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

A service member of pro-Russian troops loads rocket-propelled grenades into an infantry combat vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops load rocket-propelled grenades into an infantry combat vehicle during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko 

An armoured vehicle of pro-Russian troops drivers along a street during fighting in Ukraine-Russia conflict near a plant of Azovstal Iron and Steel Works company in the southern port city of Mariupol, Ukraine April 12, 2022. REUTERS/Alexander Ermochenko