More than 660,000 refugees flee Ukraine: UN

More than 660,000 refugees have fled the conflict in Ukraine to seek shelter in neighbouring countries, the UN Refugee Agency said Tuesday.

"We have now over 660,000 refugees who have fled Ukraine to neighbouring countries in the past six days alone," spokeswoman Shabia Mantoo told reporters in Geneva.

"The numbers are exponentially increasing... At this rate, the situation looks set to become Europe's largest refugee crisis this century."