Police are pursuing gunmen who raided a village in Ukasi, Kitui County, and killed a 28-year-old man.
The gunmen also shot and injured two others in the attack whose motive is yet to be known.
Police said they were called to the area and found the body of one Sebastian Muli lying in a pool of blood.
Two other men were found with gunshot wounds a few meters away on the eve of New Year's Day.
Police said the survivors told them the attackers escaped on a Probox car that had ferried them there after the mission.
One of the men was shot in the back and the second one in the hand and were admitted to Mwingi Level Four Hospital.
The motive of the attack is yet to be known, police said.
Police said they recovered six spent cartridges from the scene.
The body was moved to the mortuary pending autopsy and further investigations.
Local administrators led by the Mwingi East DCC Patrick Momali visited the scene and urged the locals to stay calm as police pursued the attackers.
The area is near the Garissa border where gunmen usually cross for attacks in retaliation in fights over grazing fields.
Herders usually cross with their animals to Kitui for pasture, which has been a source of conflict.
An operation is planned in the area to flush out gunmen who have been terrorizing locals.
There are fears terror groups may take advantage of the conflict and cross into the area for a mission.
Officials say they have mounted roadblocks on the road and increased patrols to address such fears.
