The UN Refugee Agency (UNHCR) said that more than 4.5 million people have fled Ukraine since Russia launched its ongoing war on February 24.
As of Sunday, the UNHCR said there were 4,503,954 Ukrainian refugees, 62,291 more than the previous day, the BBC reported.
According to the UN agency, this is the first time for Europe to witness such a large number of refugees since the Second World War.
