Around 10 million Ukrainians, more than a quarter of Ukraine's population, have fled their homes due to Russia's "devastating" war, the United Nations High Commissioner for Refugees (UNHCR) chief said Sunday.

"Among the responsibilities of those who wage war, everywhere in the world, is the suffering inflicted on civilians who are forced to flee their homes," said UNHCR chief Filippo Grandi.

"The war in Ukraine is so devastating that 10 million have fled either displaced inside the country, or as refugees abroad."

UNHCR said Sunday that 3,389,044 Ukrainians had left since the Russian invasion began on Feb. 24, with another 60,352 joining the exodus since Saturday's update – a flow roughly the same as the day before.

Some 90% of those who have fled are women and children. Ukrainian men aged 18 to 60 are eligible for military call-up and cannot leave.

UNICEF said more than 1.5 million children are among those who have fled abroad, warning that the risks they face of human trafficking and exploitation are "real and growing."

The U.N.'s International Organization for Migration (IOM) also said that as of Wednesday, 162,000 third-country nationals had fled Ukraine to neighboring states.

Some 6.48 million people are estimated to be internally displaced within Ukraine as of Wednesday, according to the U.N. and related agencies, following an IOM representative survey.

UNHCR initially estimated that up to 4 million people left Ukraine. Before the conflict, 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./AFP