At least 75 armed men have been killed in four days of clashes with army troops in west of Uganda near its border with the Democratic Republic of the Congo (DRC), the army said.

Army spokesman Ninsiima Rwemijuma said on Tuesday that the operation came to protect a tribe from coordinated attacks by the gunmen in the region.

Some five soldiers, five policemen and 11 civilians were also killed in the clashes in mountainous and rural region near the DR Congo border.

Attackers armed with machetes, spears and guns carried out several attacks on Saturday and Sunday to kill neighboring rivals.

Uganda President Yoweri Museveni pledged in a speech to "punish those involved" in a "criminal scheme that has caused the death of so many people."

Fighting is reportedly ongoing between the army and gunmen, with Rwemijuma saying, "We expect no more civilians dying because we have deployed enough forces on the ground and neutralized attacks.”

Uganda police spokesman Fred Enanga said the attacks are ethnic battles, with majority Bakonzo tribal gunmen trying to kill the Basongora people because of "long-standing differences of culture and over land."

"Had it not been timely intervention of the security forces, it could have reached an extent that the whole minority group was wiped out," he also said.