The UN Refugee Agency (UNHCR) says more than 874,000 people have fled Ukraine since Russia’s invasion last week and the figure is “rising exponentially”, putting it on track to cross the one million mark possibly within hours.

UNHCR spokeswoman Shabia Mantoo said on Wednesday that people are continuing to stream into Ukraine’s neighbouring countries to the west, with more than 200,000 fleeing since Tuesday.

A day earlier, Ms Mantoo said the outflows from Ukraine could make it the source of the “biggest refugee crisis this century” — eclipsing the one from Syria’s war over the last decade.

She said the UNHCR had previously projected that as many as four million people might flee Ukraine, but noted that the agency will be re-evaluating its forecast.

The latest figures show that more than half — or nearly 454,000 — have gone to Poland, more than 116,300 to Hungary and over 79,300 to Moldova. Another 69,000 have gone to other European countries and 67,000 have fled to Slovakia.

Ms Mantoo noted that the figure of 874,000 was an increase from more than 660,000 only a day earlier — and some 116,000 on Saturday, in the wake of Russia’s invasion of Ukraine on February 24.