A child fleeing Russian invasion of Ukraine reacts at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

A woman cries next to her children after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

People who have fled the Russian invasion in Ukraine, wait to board a bus bound for a refugee centre established in Przemysl, in Medyka, Poland, February 28, 2022. REUTERS/Bryan Woolston 

A child fleeing the Russian invasion of Ukraine looks out of the window of a bus, at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

People who have fled the Russian invasion in Ukraine wait to board a bus bound for a refugee centre established in Przemysl, in Medyka, Poland, February 28, 2022. REUTERS/Bryan Woolston 

A woman who has fled the Russian invasion in Ukraine waits to board a bus bound for a refugee centre established in Przemysl, in Medyka, Poland, February 28, 2022. REUTERS/Bryan Woolston 

An Afghan family, who once fled the war in Afghanistan, wait to board a bus bound for a refugee centre, after fleeing the Russian invasion in Ukraine, in Medyka, Poland, February 28, 2022. REUTERS/Bryan Woolston 

People who have fled the Russian invasion in Ukraine, wait to board a bus bound for a refugee centre established in Przemysl, in Medyka, Poland, February 28, 2022. REUTERS/Bryan Woolston 

A woman cries after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A woman fleeing Russian invasion of Ukraine plays the guitar at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi TPX IMAGES OF THE DAY 

A person fleeing Russian invasion of Ukraine reacts at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

People fleeing Russia's invasion of Ukraine, cross train tracks to get to a train leaving for Poland, at the train station in Lviv, Ukraine February 28, 2022. REUTERS/Thomas Peter 

People fleeing Russia's invasion of Ukraine, wait at Lviv train station to catch a train to Poland, in Lviv, Ukraine February 28, 2022. REUTERS/Thomas Peter 

People fleeing Russia's invasion of Ukraine, wait at Lviv train station to catch a train to Poland, in Lviv, Ukraine February 28, 2022. REUTERS/Thomas Peter TPX IMAGES OF THE DAY 

People fleeing Russia's invasion of Ukraine, wait in a crowded underpass at Lviv train station to catch a train to Poland, in Lviv, Ukraine February 28, 2022. REUTERS/Thomas Peter 

People fleeing Russia's invasion of Ukraine, cross train tracks to get to a train leaving for Poland, at the train station in Lviv, Ukraine February 28, 2022. REUTERS/Thomas Peter 

A girl hugs her friend who fled Russian invasion of Ukraine, after arriving at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

A volunteer talks to a woman and children who fled from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A girl is pictured inside a bus after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A child fleeing Russian invasion of Ukraine holds a toy at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

A woman carries a child as they board a bus after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A woman holds a child after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A woman fleeing Russian invasion of Ukraine holds a dog at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

A mother feeds her child after they fled Russia's invasion of Ukraine and rest at a refugee shelter in Beregsurany, Hungary, February 28, 2022. REUTERS/Bernadett Szabo 

A woman fixes her luggage after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A man carries a child after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

A mother gives water to her daughter as they flee Russian invasion of Ukraine, at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi 

A woman reacts after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

Children board a bus after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania, February 28, 2022. REUTERS/Stoyan Nenov 

People fleeing Russian invasion of Ukraine stand at a temporary camp in Przemysl, Poland, February 28, 2022. REUTERS/Yara Nardi