The two officials; South Constituency Development Manager Mark Erukudi and Environment officer Maxwell Loko were shot dead on the evening of Wednesday by suspected armed bandits from neighbour West Pokot County.
Nanok said the culprits must be apprehended to face the law.
"The fresh wave of insecurity would reverse gains of peace efforts that had reduced regular cases of attacks in the Sub-County," Nanok said.
The Governor led Turkana community to return stolen animals of West Pokot community in a show of peace.
"The return of livestock stolen both from the West Pokot and Turkana side is a great thing that will promote peace among the communities," Nanok said.
Turkana South MP James Lomenen asked security officers to speedy their investigations to arrest suspected bandits who killed the county officials.
His Turkana East counterpart Ali Lokiru said leaders should extend peace drive to address conflict at the border with Baringo and West Pokot counties.