Four people were shot dead and several others injured while another one was reported missing following clashes between two communities in Mutuati area of Meru County.
The four were killed in a series of attacks and counter attacks that began on Sunday evening by unknown gunmen.
Mr Willy Harun, 28, was shot and killed as he travelled on a motorcycle from Mutuati market to Gachiuru area.
The motorcycle rider, whose name was not immediately established, also suffered back injury and is recuperating at Maua Methodist Hospital.
Igembe North police boss David Kirui said the killings which occurred at Lumbaini Hills, triggered a retaliatory attack where armed raiders attacked Kiolu village and killed Mr Samuel Mugambi, 35.
“They were waylaid by gun toting people who flagged the rider to stop but he defied their orders. They opened fire and killed the passenger on the spot while the same bullet injured the rider,” Mr Kirui said.
The gunmen robbed the traders of money and the motorcycle.
They also attacked a makeshift homestead at Kongo Atune where herdsmen were having a meal and started shooting indiscriminately at the three occupants, killing Mr Benjamin Kamilu, 32, on the spot.
Mr Kirui said they found a mutilated body thought to be that of one of the missing herdsman during a patrol.
Area leaders including Igembe North MP Maoka Maore and Amwathi MCA John Ntongai called for increased security.
He said there had been simmering tensions between Borana and Somali livestock traders.
Mr Kirui said they were investigating the claims to establish whether the first incident was actually a case of robbery with violence or staged attacks guided by business rivalry.
“It is as if the two communities are engaged in business rivalry and one wants the other to stop trading directly with the Meru,” he said.
He said they had intensified patrols in the area to apprehend the attackers.