Five people were on Sunday morning shot and killed in Forore, Marsabit County, by suspected Ethiopian militia.
Steve Oloo, County Police Commander, said four other people were injured in the 4.am attack along the Kenya-Ethiopia border.
The officer stated that those killed were two boys and a girl aged between 13 and 15 years.
After the attack, the group stole cows before crossing over to Ethiopia.
The attack comes just hours after the national population and housing census exercise kicked off last night.
North Horr Member of parliament Chachu Ganya expressed his fears that tension in the area might affect the census exercise.
He noted residents might not participate due to fear of more attacks.
The attack comes days after Wajir North MP, Ahmed Ibrahim Abdsalan, was shot at by unknown gunmen during a census sensitization meeting.
The assailants also torched his vehicle.
The legislator was travelling with the census staff when the attack occurred near an abandoned mosque at Masalale.
He was luckily rescued from the scene by his security team.