When lightning and thunder erupted on Friday, the Dodoth warriors mobilised themselves and rushed to the grazing area to protect their cattle.
Army spokesman Major Phinehas Katirima said the herders were from two rival groups within the Karamojong tribes in Kotido district.
He said the Ugandan army was hunting some of the herders who fled with about 300 cattle.
This is the second reported attack in a month in Karamoja where armed herders frequently mount attacks to seize livestock from rival tribes.
An local army spokesman said the bodies of the dead still littered the area as the Karamojong tradition does not allow burial of warriors killed in battle.
Eyewitnesses say the two rival ethnic groups, the Jie and the Dodoth, fought for two days.
About 80 Jie warriors were killed and around 15 Dodoth men died.
Forewarned
People coming from the region said the Dodoth were forewarned by a local shaman who reportedly predicted the imminent raid by the Jie, warning that the attack would take place after a storm.
When lightning and thunder erupted on Friday, the Dodoth warriors mobilised themselves and rushed to the grazing area to protect their cattle.
They laid an ambush for the unsuspecting Jie warriors and a two-day battle ensued.
The Ugandan army is now hunting the Jie raiders, who fled with about 300 cattle, but have not yet found them.
Disarmament
Earlier this year the government announced plans to start disarming the Karamojong in July, but the process has not yet begun.
"We are assembling the necessary logistics and troops, and preparing for this exercise," said Major Katirima.
The operation is expected to take up to a year. Military analysts believe there are up to 100,000 guns in Karamoja - perhaps twice the number held by the Ugandan army.
The Karamoja region has also been hit by severe food shortages which have resulted in a number of deaths.
According to local authorities in Katikekile, more than 100 people have already died of hunger-related diseases.