GENEVA, April 17 (AFP) - The head of the UN refugee agency hoped on Sunday (Apr 17) that peace would prevail over war, with more than 4.8 million Ukrainians having fled their country since the Russian invasion.

"As Christians celebrate resurrection on this sombre Easter Sunday, we must stubbornly hope that in the days, months and years to come the methods and language of war will not prevail over those - more difficult, more complicated - that lead to peace," said UNHCR chief Filippo Grandi.

UNHCR said 4,869,019 million Ukrainians had left the country since Russia invaded on Feb 24 - up 32,574 on Saturday's total.

The UN's International Organization for Migration (IOM) says nearly 215,000 third-country nationals - largely students and migrant workers - have also escaped to neighbouring countries, meaning more than five million people in all have fled Ukraine since the war began.

It is one of the fastest-growing displacement and humanitarian crises ever.

More than 2.75 million Ukrainian refugees have fled to Poland. Nearly 740,000 reached Romania.

UNHCR figures show nearly 645,000 Ukrainians fled in February, with nearly 3.4 million doing so in March and more than 830,000 leaving so far this month.

Women and children account for 90 per cent of those who escaped, with men aged 18 to 60 eligible for military call-up and unable to leave.

Nearly two-thirds of all Ukrainian children have been forced from their homes, including those still inside the country.

Beyond the refugees, the IOM estimates 7.1 million people have left their homes but are still in Ukraine.

"In this season of renewal, our thoughts are with all those who have been forced to flee their homes and have had to rebuild the life they left behind," the UNHCR 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.