The raiders, suspected to be Shabaab fighters, attacked Dadajabula village located less than 20km from the Somali border.
"The incident is under investigation, but we have beefed up security along that border area to safeguard our country against such attacks," North Eastern Provincial Commissioner James Ole Serian said.
"We do not know specifically which militia group it was because there are a lot of small groups of militias operating in Somalia, but we suspect it has something to do with al-Shabaab," he said.
Last week, Shabaab spokesperson Sheikh Ali Mohamoud Rage warned Kenya not to interfere in the Somali conflict.
Since the embattled Western-backed Somali transitional government started planning a major offensive to root out the insurgency, the Shabaab have accused Kenya of being an integral part of the operation.
Kenya has consistently denied any involvement in the Somali conflict but intelligence reports suggest it has been supporting militias opposed to the Islamist insurgency along its long and porous border with Somalia.