The UN migration agency estimates that nearly 6.5 million people have now been displaced inside Ukraine, on top of the 3.2 million refugees who have already fled the country.

The estimates from the International Organisation for Migration suggests Ukraine is fast on a course in just three weeks toward the levels of displacement from Syria's devastating war which has driven about 13 million people from their homes both in the country and abroad.

The findings come in a paper issued Friday by the UN Office for the Coordination of Humanitarian Affairs.

It cited the IOM figures as a good representation of the scale of internal displacement in Ukraine calculated to stand at 6.48 million internally displaced persons in Ukraine as of March 16. (AP)