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The number of people who have fled the war in Ukraine has reached 6,029,705, figures from the UN Refugee Agency show.
More than half have gone to Poland, where 3,272,943 refugees are registered, according to UNHCR data.
“The scale of human suffering and forced displacement due to the war far exceeds any worst-case scenario planning,” said Antonio Vitorino, Director General of the UN's International Organisation for Migration (IOM).
Women and children represent 90 per cent of the refugees, with Ukrainian men aged 18-60 unable to leave due to being eligible for military service.
Romania has welcomed 895,828 refugees, while Hungary has accepted 583,066.
The figures show 459,546 Ukrainians have fled to Moldova, 409,527 to Slovakia and 27,308 to Belarus.
A total of 785,348 Ukrainians have arrived in Russia since the full-scale invasion of Ukraine was launched on February 24.
While the outflow has slowed significantly since March, the UNHCR has projected that three million more Ukrainians could become refugees by the end of the year.
The exodus has been described as Europe's fastest-growing refugee crisis since the Second World War, but a leading humanitarian has called this an understatement.
The UN earlier this week said more than 8 million Ukrainians had been internally displaced by the Russian invasion of their country. The figures issued by the IOM is up from the 7.7 million figure the agency issued in mid-April.
“The needs of those internally displaced and all affected by the war in Ukraine are growing by the hour,” Mr Vitorino said.
“Access to populations in need of aid remains a challenge amid active hostilities, but our teams are committed to continue delivering urgent assistance inside Ukraine and in neighbouring countries.”
More than 12 million were displaced in the first eight weeks of the war, Jan Egeland, Secretary General of the Norwegian Refugee Council, told reporters.
“People talk about since the Second World War, [but] tell me when in the Second World War there were 12 million people displaced in eight weeks,” Mr Egeland said.
The large displacements back then happened “over a longer period”, he said.
UN Secretary General Antonio Guterres travelled to Moldova this week where he met Ukrainians who had sought refuge in their neighbouring country, telling reporters “it is impossible to meet refugees and not be deeply moved by their stories.”
“One couple was telling me of a bomb that fell in their yard. People that have abandoned everything, including parts of their families,” Mr Guterres told reporters, in Moldova’s capital Chisinau.
In addition to the Ukrainian refugees, the IOM said that as of April 26 an additional 224,975 citizens of third countries — largely students and migrant workers ― had escaped to neighbouring countries since the invasion began.
Almost two thirds of Ukrainian children have been displaced from their homes.
The war in Ukraine is a “child rights crisis” where education is under attack, nearly 100 youngsters have been killed in just the last month, and millions more have been forced to flee their homes, the UN children’s agency said Thursday.
Omar Abdi, deputy executive director of Unicef, told the UN Security Council that children are paying “an unconscionably high price” in the war, with 239 confirmed killed and 355 wounded since Russia’s invasion of Ukraine on February 24. He said the actual numbers are much higher.
“These attacks must stop,” he said. “Ultimately, children need an end to this war — their futures hang in the balance.”
Mr Abdi said the school year came to a standstill after Russia invaded its smaller neighbour, and as of last week at least 15 of 89 Unicef-supported schools in the country’s east had been damaged or destroyed in the fighting.
“Hundreds of schools across the country are reported to have been hit by heavy artillery, air strikes and other explosive weapons in populated areas, while other schools are being used as information centres, shelters, supply hubs, or for military purposes — with long-term impact on children’s return to education,” Mr Abdi said.
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-controlled regions in the east of the country.
EU and national leaders have been keen to talk of open borders and welcoming refugees.
But moving across the continent is not easy, particularly for those who leave with few or no belongings and limited money.
The 27-nation bloc is preparing to grant Ukrainians the right to stay and work for up to three years, reviving a law that has been dormant since the collapse of Yugoslavia in 1992.
UN's co-ordinated response
The UNHCR has not been limited to documenting the Ukrainian diaspora. It has also co-ordinated a humanitarian response, including attempting to send money to those who have fled.
It began a cash enrolment scheme in Ukraine on March 27. Latest figures show 162,015 people have been enrolled to receive cash assistance and 96,357 have received their first payments.
Support extends beyond financial help, too.
Almost 100,000 people have received targeted protection assistance at border-crossing points, online, and in the locations to which they have fled. This includes protection counselling and services, including psycho-social support and legal aid.
To date, almost 305,000 people have benefited from core-relief items and food assistance across eastern, central and western Ukraine. This includes more than 56,500 who have received food assistance, while the remainder have received core-relief items, winter clothes, or emergency shelter and support.
There are challenges in delivering support in such breadth and depth. The UNHCR has said “access to the hardest-hit areas remains extremely challenging, with continuing security risks, both for affected civilians as well as humanitarian actors”.