Thousands flee Ukraine amid Russian invasion; see pics

A woman cries next to her children after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania.

A girl hugs her friend who fled Russian invasion of Ukraine, after arriving at a temporary camp in Przemysl, Poland.

A person fleeing Russian invasion of Ukraine reacts at a temporary camp in Przemysl, Poland.

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.

A woman reacts after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania.

A woman cries after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania.

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.

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.

People fleeing Russian invasion of Ukraine stand at a temporary camp in Przemysl, Poland.

Children board a bus after fleeing from Russia's invasion of Ukraine, at the border crossing in Siret, Romania.