Two officers and a soldier were killed and one was wounded, while two civilians were injured by stray rounds, regional military spokesman Major Dieudonne Kasereka told reporters.

No details were available about any losses among the assailants.

The raid happened late Monday morning, when so-called Mai-Mai militiamen -- members of an ethnic armed group -- attacked Uvira from the surrounding hills with the support of Burundian rebels, he said.

The group wanted "to loot people's property and get food supplies", he said.

The city, which has a population of several hundred thousand, lies on the northern shore of Lake Tanganyika, which the Democratic Republic of Congo shares with Burundi.

The assailants were repulsed after eight hours' fighting, and the situation is "under control", Kaseraka said.

Uvira lies in South Kivu, which has been grappling with ethnic violence for more than a quarter of century, after armed groups emerged along community lines on the back of two bloody wars.

On November 3, 11 people, six of them rebels, died when a group raided the provincial capital Bukavu and clashed with Congolese troops.