Police had warned a group of Turkana herders against migrating before they were attacked at the Kenya-South Sudan border, according to County Police Commander Samuel Ndanyi.
One person died and two others were left with serious injuries during the incident.
The attackers are suspected to be from Toposa in South Sudan.
Ndanyi, on Tuesday, said security officers had warned the affected Kraal against migrating without a plan for their safety but they defied.
“Our officers had warned them of lurking danger but the herders ignored and migrated with their animals,” Ndanyi said.
He said heavily armed militia who had been monitoring the movement of the herders ambushed them at Kaamuny Napas in Mogila. They opened fire, killing one person and injuring two others.
Ndanyi who termed the attack unfortunate said the militants also stole an unknown number of cattle from the herders.
He said the chances of the security officers recovering the livestock were slim.
“Our security officers pursued the assailants but, unfortunately, they could not catch up with them since they had already crossed the border with the animals,” Ndanyi said.
The attack occurred a week after the government had trained National Police Reserves officers at Lokichoggio camp and deployed them to various Kraals at border points.
“This was just an isolated incident that could have been averted had the herders heeded the security warning,” he said.
