The U.N. refugee agency says at least 125,000 people in Yemen have fled their homes since August because of the conflict between government forces and tribal groups.
The office of the U.N. High Commissioner for Refugees says the total displaced population in Yemen has reached a quarter of a million since the conflict flared up in 2004.
UNHCR spokesman Andrej Mahecic says that as the fighting has moved away from the main northern city of Saada it is driving civilians from areas further northwest from their homes as well.
He says the collapse of the local economy is also increasing the flow of displaced persons.
Mahecic told reporters in Geneva on Friday that "people simply cannot sustain themselves any longer in Saada province."