By Hez Holland
GOMA, Congo, Oct 28 (Reuters) - Congolese Tutsi rebels overran the eastern town of Rutshuru on Tuesday, a rebel spokesman said, forcing tens of thousands of people to flee.
He said the rebels loyal to renegade General Laurent Nkunda had also encircled the provincial capital Goma, 100 km (60 miles) to the south. That could not be independently verified.
"We have taken the town of Rutshuru and the (adjoining) town of Kiwanja," Bertrand Bisimwa, from the rebel group the National Congress for the Defence of the People (CNDP), told Reuters.
The U.N peacekeeping mission MONUC said rebels were in Rutshuru, but that peacekeeping forces were also in the town and there was no fighting.
"MONUC confirms CNDP presence in the town of Rutshuru," spokesman Michel Bonnardeaux said. "We are there to protect the civilian population despite the fact that the FARDC (Congolese army) has fled the area."
The head of the government army's operations in the area, Colonel Delphin Kahimbi, said earlier he would have to abandon Rutshuru in the face of the rebel advance that began on Sunday.
U.N. peacekeepers had to scrap an attempt to evacuate around 50 foreign aid workers from Rutshuru, in North Kivu province, earlier on Tuesday.
"The situation is very tense. They were blocked by both the population and soldiers. There are also attacks on humanitarian installations and looting," said Evo Brandau, spokesman for the U.N. humanitarian office OCHA.
"The army is no longer guaranteeing security."
The provinces of North and South Kivu are home to the majority of Congo's tin ore deposits, but most foreign investment is concentrated on Katanga, the copper-mining province in the southeast of the country.
REFUGEES FLEE AGAIN
Rutshuru normally shelters tens of thousands of internal refugees displaced by nearly two years of on-off fighting, but Kahimbi said the camps had emptied.
The U.N. refugee agency UNHCR said it was preparing for the arrival of 30,000 people at its Kibati camp 10 km (6 miles) north of Goma, including 20,000 from the village of Kibumba, 20 km from Goma, which insurgents attacked on Monday.
MONUC helicopters attacked rebel positions north of Goma on Monday, drawing anti-aircraft fire from Nkunda loyalists.
"MONUC will use all available means to protect urban centres including Rutshuru, Sake (to the west of Goma), and Goma," said Bonnardeaux of MONUC, whose 17,000 personnel are mostly deployed in Congo's east.
Nkunda's CNDP accuses Congo's army of collaborating with the Democratic Forces for the Liberation of Rwanda (FDLR), which includes Hutu militias and former Rwandan soldiers responsible for Rwanda's 1994 genocide of Tutsis and moderate Hutus.
Around 250,000 civilians have fled their homes in North Kivu since a January peace deal collapsed in August. Nearly two years of sporadic fighting had already displaced around 850,000 people before the latest fighting began, according to U.N. figures.
Congo's 1998-2003 war and the resulting humanitarian crisis have killed an estimated 5.4 million people.