Karamojong fighters attacked the village of Opeuru Aodot, 175 miles northeast of the capital, Kampala, at around noon Saturday, said resident district commissioner Ndiwa Chemasuet.
"They just came and shot people savagely. They shot anybody on sight. They killed 21 people and most of these were women and children who were at home," Chemasuet said by telephone from his office in Katakwi district. "We have rushed five seriously injured people to Soroti hospital. It has been a disaster for us."
Chemasuet said that after finding 21 bodies in the village, a sweep of the savannah around the village produced nine more bodies.
"What happened is that some people ran to the bushes and gardens with fatal wounds and died there ... We are moving deep into the bushes and gardens to look for more bodies. We believe that many bodies might still be scattered there," Chemasuet said.
The Karamojong, a nomadic tribe with a strong warrior tradition, has raided neighboring tribes — and even clans within the tribe — for centuries.
With the flow of modern military weaponry into East Africa, the raids have become much larger and more deadly.
The Ugandan army has waged an aggressive campaign to disarm the Karamojong over the past three years and reduce tribal fighting, but the tribesmen have been reluctant to hand over their weapons.
Only a quarter of the 40,000 guns in the hands of the tribesmen have been collected, according to army estimates.