Pedestrians are seen in a street in Beni, in the north-eastern DRC. Picture: Alain Wandimoyi

Kinshasa - The Congolese army on Tuesday clashed for a second day with suspected Ugandan rebels blamed for recent massacres in the country's volatile east, civil society and UN sources told AFP.

The battles broke out on Monday when troops attacked rebels who were thought to be organising another possible assault on the large town of Beni in the North Kivu province.

A member of the Beni region's civil society movement told AFP that the latest clashes have killed one army officer and two rebels, according to the the military.

Troops of the large UN peacekeeping mission in the country, MONUSCO, were participating in the fighting, a source with the force told AFP on condition of anonymity.

The UN soldiers, boosted by a tough Security Council mandate to take the offensive against armed groups rife in the east, have engaged in “other important (operations) carried out in parallel” with actions alongside the national army, the source said.

Scores of civilians have been killed since the start of October in vicious raids blamed on the rebels of the Allied Democratic Forces and National Army for the Liberation of Uganda (ADF-NALU), who terrorised parts of the resource-rich region for almost two decades.

On Monday, North Kivu's governor Julien Paluku reported “contact” between government soldiers and “the ADF rebels close to the outskirts of Beni town, inside the Virunga National Park,” famed for its endangered mountain gorillas.

The mainly Muslim rebels have been hiding out in the Ruwenzori mountains that straddle the border with Uganda since being driven out of their homeland by President Yoweri Museveni's soldiers in 1995.

The rebels have been blamed for a series of atrocities, pillaging villages, hacking men, women and children to death and forcing locals to work for them for years, while funding themselves from the lucrative illegal smuggling of timber.

While they killed about 120 people in the past five weeks and thousands of families fled to seek safety elsewhere, Beni's civil society urged President Joseph Kabila to declare a state of emergency.

Kabila paid a brief visit last week and vowed to wipe out the ADF-NALU. An overnight curfew was imposed on the trading town of about half a million people on Sunday.

In January, the Congolese army and MONUSCO soldiers launched an offensive against the ADF-NALU, the last major insurgent group active in the northeastern region.

Initially, the combined forces thought they had severely weakened them, but the rebels have bounced back since the death in August from a heart attack of Congolese General Jean-Lucien Bahuma.

A brilliant tactician and regional army chief in North Kivu until he died, Bahuma became renowned for masterminding operations that led to the total defeat last year of another rebel movement known as M23.