GENEVA: More than 3.5 million people have fled Ukraine since Russia’s invasion nearly a month ago, the United Nations said Tuesday, adding the scale of the tragedy “far exceeds any worst-case scenario planning.”

More than 10 million people – over a quarter of the population in regions under government control before the February 24 invasion – are now thought to have fled their homes, including the millions of internally displaced people.

UNHCR, the UN refugee agency, said 3,557,245 Ukrainians had fled the country – a figure up 67,601 from Monday’s update.

“The speed and the scale of this outflow and this displacement crisis is unprecedented in recent times,” UNHCR spokesman Matthew Saltmarsh told reporters in Geneva, recalling the “tragic milestone” has been reached in just under a month.

The UNHCR said Ukraine’s refugee crisis is Europe’s worst since World War II.

Women and children account for some 90 percent of those who have fled. Ukrainian men aged 18 to 60 are eligible for military call-up and cannot leave.

UNICEF, the UN children’s agency, said more than 1.5 million children are among those who have fled abroad.

Antonio Vitorino, head of the UN’s International Organization for Migration (IOM), said: “The scale of human suffering and forced displacement due to the war far exceeds any worst-case scenario planning.”

The IOM said an additional 186,000 people from third countries had fled Ukraine.

As of Wednesday, some 6.48 million people were estimated to be internally displaced within Ukraine, according to an IOM representative survey.

Nearly 3.5 million Ukrainians flee the country: UN

Before the invasion, Ukraine had a population of 37 million in the regions under government control, excluding Russia-annexed Crimea and the pro-Russian separatist regions in the east.

Here is a breakdown of neighbouring countries that have welcomed Ukrainian refugees, according to UNHCR:

Poland

Six in every 10 Ukrainian refugees – 2,113,554 so far – have crossed the Polish border, according to UNHCR’s latest figures.

Many of those heading west from Ukraine into Poland, Hungary and Slovakia then travel further on into other states in Europe’s Schengen open-borders zone.

Paloma Cuchi, the World Health Organization’s representative in Poland, said children had not eaten properly, while a “tremendous number” of senior citizens had been without their medication for days and were arriving with diabetes, blood pressure and other health problems.

Cuchi told reporters in Geneva that many refugees suffered from fever, diarrhoea, hypothermia, upper respiratory tract infections, cardiac arrests, and mental and emotional distress.

Romania

UNHCR said 543,308 Ukrainians had made their way into EU member Romania, including a large number who have crossed over from Moldova, wedged between Romania and Ukraine.

The vast majority are thought to have made their way onto other countries further into Europe.

Moldova

The Moldovan border is the nearest to the major port city of Odessa.

UNHCR said 367,913 Ukrainians had crossed into the non-EU state, one of the poorest in Europe. Most transit through the small nation, en route westwards to Romania and beyond.

Hungary

The number of Ukrainian refugees who have crossed into Hungary has reached 317,863, UNHCR said.

Slovakia

A quarter of a million people have made it across Ukraine’s shortest border into Slovakia, the UNHCR said, at 253,592 Ukrainian refugees.

Russia

Some 252,376 refugees have sought shelter in Russia since the invasion began.

In addition, UNHCR said 113,000 people had crossed into Russia from the separatist-held pro-Russian regions of Donetsk and Lugansk in eastern Ukraine between February 21 and 23.

Belarus

And 4,308 refugees have made it north to Belarus, UNHCR says.