The UN migration agency on Tuesday estimated that more than 11 million people had fled their homes in Ukraine since Russia's invasion.

The International Organisation for Migration, in its first such full assessment in three weeks, reported that more than 7.1 million had been displaced within Ukraine as of April 1.

The latest numbers came on top of the figure of more than four million people who fled abroad, reported by the UN refugee agency.

IOM said more than 2.9 million others were actively considering "leaving their place of habitual residence due to war".

Ukraine had a pre-war population of 44 million.

The tally marked an increase from IOM's tally in mid-March of more than 9.7 million displaced internally in Ukraine or driven abroad.