Herders burnt down several houses and acres of pasture at Tanna trading centre in Garba-Tula.
Hundreds of Auliyan herders, who had crossed into Isiolo from Lagdera and Garissa, have been fleeing Garba-Tula since Friday.
They invaded the area mid last year in search of pasture and water, but were forced to leave due to clashes between them and the host Borana herders. Six people were killed in the clashes.
The latest killing happened over the weekend. Mahat Sagar, a herder from Lagdera, was gunned down outside Garba-Tula on Sunday, the authorities said.
Three other people who had been reported missing were found alive by police, according to Garba-Tula Deputy County Commissioner Kipchumba Rutto.
On Sunday evening, migrant herders attacked a convoy of vehicles heading to Garba-Tula from a market in Skot and engaged escorts comprising Kenya Police Reservists in a gun fight.
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Abdullahi Huka, a reservist, was shot in the leg and taken to a hospital in Meru.
Rutto said the fleeing migrant herders burnt down nine houses out of a settlement of 49 and pastureland at Tanna. The area has several springs.
“Some of the houses are semi-permanent. We do not know the acreage of grass-cover that was burnt down. The police are currently investigating,” said the administrator.
County Assembly Speaker Mohammed Tubi and Garba-Tula MCA Abdi Sora described the incident as ‘sabotage against the people of Isiolo’.
“We hosted them in their time of need and they pay us back by killing our people, burning down houses and large tracts of grazing land,” said Mr Tubi.
Mr Sora said the migrant herders were still in Garba-Tula, adding that they were found a few kilometres from the town centre, Skot, near Duse and on spots along the Garba-Tula-Modogashe road.
The MCA called on Interior Cabinet Secretary Joseph Nkaissery to intervene as he did in Mwingi, Kitui County, by ordering the eviction of migrant herders.
Villages in several locations remain deserted due to heightened tension between the rival sides. Areas affected include Tanna, Boji and Baranbate.
Centres in Gafarsa that were hit by a wave of insecurity from last September still remain deserted.
“Belgish, which has adequate pasture and water pans, has been deserted since September last year. The only school in the area was closed and is yet to be reopened,” said Sora.
In Garba-Tula town, business stops at dusk for fear of attacks.
“All business premises close before sunset and everyone remains indoors,” said a man who identified himself only as Sime.
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All vehicles using Garba-Tula-Kinna, Garba-Tula-Modogashe among other routes are now forced to seek police escort.
Rutto said there was enough security personnel to deter retaliatory attacks between the two rival sides.