More than 15,000 people including Malian military personnel have fled into neighboring countries since members of the nomadic Tuareg ethnic group launched a new rebellion against the Malian government last month, aid officials say.
Some civilians are fleeing areas where fighting is taking place, while others fear there could be revenge attacks against those believed to be Tuareg. Already at least one Tuareg family's home has been attacked near the capital of Bamako.
The International Committee of the Red Cross says 10,000 people have crossed into Niger after fighting in towns just across the border, and the ICRC is preparing to provide food and shelter.
"Some of these people have been taken in by villagers, but the local capacity was very quickly overwhelmed," said Juerg Eglin, head of ICRC delegation for Niger and Mali.
Another 5,000 people have fled to Mauritania, according to an official who works at an international humanitarian organization based in Mauritania's capital. The official spoke on condition of anonymity because she was not authorized to provide figures to the media.
The Tuaregs, a traditionally nomadic people spread across the Sahara Desert, have risen up against the central government in Mali several times since the country's independence from France in 1960.
The newest rebellion launched in January broke years of relative peace, and is being fueled by the return of Tuaregs from Libya who had fought in Moammar Gadhafi's army. In the last two weeks, the Tuareg group has attacked six towns spread out over more than 500 miles (800 kilometers) across Mali's vast north.
A group calling itself the National Movement for the Liberation of the Azawad was formed in October and seeks self-determination of the north of Mali. The Malian government has accused the group of fighting one battle with al-Qaida's North Africa branch, which is active in the region. The MNLA denies the accusation.
Among those fleeing to Niger were military personnel and their families, said Franck Kudzo Kuwonu of the Office for the Coordination of Humanitarian Affairs in the capital Niamey.
Although there is no evidence that those with northern features are being systematically targeted in Mali on a wide-scale basis, there is a tangible sense of panic among Tuareg and those who feel they might be mistaken for Tuareg. Even people from countries such as Algeria, Morocco and Tunisia have been leaving Mali, concerned that they might be mistaken for Tuareg.
On Wednesday, Mali's president addressed the nation pleading with people not blame Tuaregs and others with northern features for the acts of just a few rebels.
"Those who attacked certain military bases and towns in the north should not be confused with our Tuareg, Arab, Fulani and Songhai compatriots who live with us," Amadou Toumani Toure said in a speech carried on state television.
The president's message, however, did not stop the protests in the capital and other southern towns like Segou and Sikasso on Thursday and Friday. Many in the south are still scared of what might happen to them.
"When you see so many people leaving, I wonder whether I've made the right decision to say," said one Arab man who has lived in Bamako for many years and spoke on condition of anonymity for fear of reprisals.
Associated Press writer Dalatou Mamane in Niamey, Niger contributed to this report.