NAIROBI - Clashes in northeast Congo forced 35,000 people to flee their homes in the past week, adding to a growing tide of residents uprooted by fighting between rebel factions, an aid agency said on Saturday. Medecins sans Frontieres (MSF) said it feared this brought the total number of people displaced by fighting in the area in recent months to an estimated 155,000.

The exodus - one of the biggest mass movements in the Democratic Republic of Congo in years - left the refugees prey to rising levels of hunger and disease as well as atrocities committed by fighters, it added.

Combatants have roasted people alive, raped women in front of their families and forced prisoners to eat human flesh, according to testimonies of people treated at health centres set up by MSF in the area in recent weeks.

"The patients we are treating in our clinics tell us really horrible stories," MSF's Nicolas Louis told Reuters by satellite telephone from the town of Beni. "I've worked in African war zones for 15 years, and what we are seeing here are among the worst things I've ever seen.

"Fighting between rebel factions in the mineral-rich former Zaire, where a four-year war has killed an estimated two million people mainly through hunger and disease, has intensified around the strategic town of Beni in the past month. The clashes have raised fears that a broad Congo peace deal signed in South Africa in December will fail to stem fighting in the chaotic war in the vast country.

MSF said rival rebel groups had fought artillery battles around the small town of Makeke on Tuesday, forcing an estimated 35,000 people out of their homes, despite the signing of a truce by various rebel factions in the area on Monday.

Louis said the area around Beni had been calm for the past few days, but it was unclear whether the truce would hold. A high-level team from the United Nations Mission in Congo (MONUC) was due to visit Beni on Monday to assess the ceasefire and meet human rights observers checking reports of massacres in the area, U.N. officials in Kinshasa said.

Fears of bloodbath

Lawless parts of northeastern Congo have been plagued for several years by clashes between various factions, often along ethnic lines, which have killed thousands of people. U.N. officials and Amnesty International have previously warned of a possible ethnic bloodbath in the area, comparable to the 1994 genocide in neighbouring Rwanda, in which 800,000 people were massacred.

MSF said "extreme levels of violence" stopped aid workers gaining access to large areas around Beni, placing many people beyond the reach of the few relief workers in the remote region. "We see only part of the displaced population," said MSF Head of Mission Philippe Hamel in a statement.

"There may be many more. We fear that in total there might be over 155,000 displaced people in the area between Butembo, Beni, Mambasa and Komanda alone," he said, referring to a cluster of towns in the mineral-rich northeast, towards the border with Uganda.

Further south, thousands of people fled this week after rebels clashed with forces backing the government of President Joseph Kabila near the lakeside port of Uvira, which has changed hands repeatedly in recent months.

Congo's warring parties signed a deal in December to share power and reunify the country that has been divided since war broke out in August 1998, sucking in six foreign armies. Many foreign soldiers have pulled out, but local militia violence has surged in the vacuum they left behind.