The violence broke out near the town of Moyale, on the border with Kenya, in a region claimed by both the Oromo, the largest ethnic group in the country, and the Somali ethnic group.
On top of the fatalities, 61 people were injured in the fighting, Fana reported, citing the Oromia regional state communication office.
Many more were displaced by the fighting in the region which has regularly been the scene of intercommunal violence.
Last year fighting between members of the two ethnic groups left more than a million people displaced.
While Ethiopia’s Prime Minister Abiy Ahmed has received international praise for his reformist agenda, since coming to power in April, a wave of intercommunal violence in several parts of the country – mostly over land issues – has marred the first few months of his rule.
Three Ethiopian students were also killed and 34 others injured after a fight on a campus escalated into deadly ethnic clashes in the west of the Horn of Africa country, the government said on Wednesday.