Kenyan police spokesman Jaspher Ombati said the raiders, believed to be Toposa tribesmen from southern Sudan, had earlier stolen over 800 animals from Naimoit village in Lokichogio near Kenya-Sudan border.

"The heavily armed attackers numbering over 50 on Wednesday besieged Naimoit village, 40 kilometers from the Kenya-Sudan border, and held the herdsmen hostage," Ombati told Xinhua by telephone.

"The herdsmen could not put up any resistance because the raiders came in large numbers and were heavily armed with AK-47 rifles," said the police spokesman.

"The police caught up with the raiders before they could cross over into Sudan where we engaged them in a three-hour fierce fire exchange along the Kenya-Sudan border," he noted.

He said the security team of more than 30 officers killed nine raiders in the rough terrain and recovered all the stolen animals.

No policeman was injured in the action. The stolen animals were later handed back to the owners.