The Kenyan Red Cross says about 10,000 people have fled villages near the Ethiopian border following a series of violent raids by cattle rustlers.
Local officials say at least seven people have been killed and thousands of livestock have been stolen by organized bandits in the past week. They say many of the stolen animals have been driven into Ethiopia.
There also have been reports of several kidnappings related to the livestock raids.
Kenyan officials have sent security forces to several northern districts to try to stop the thefts and the clashes between animal herders and rustlers.
Cross-border livestock raids are common in northern Kenya, a poor and arid region where clans often fight over scarce resources.