(Adds further detail of fighting, previous story KAMPALA)

By Joe Bavier

KINSHASA, Sept 4 (Reuters) - Ten thousand Congolese refugees have fled to neighbouring Uganda to escape growing clashes in eastern Congo between the army and renegade troops, the United Nations said on Tuesday.

Violence has intensified in eastern Democratic Republic of the Congo recently and Congo's army said it killed at least 28 fighters loyal to rebel Tutsi General Laurent Nkunda on Monday in exchanges of fire lasting several hours.

On Tuesday, fighting broke out in a national park that is home to rare mountain gorillas.

"The displaced said they were fleeing fighting between the government army and militia led by General Laurent Nkunda," the United Nations refugee agency (UNHCR) said in a statement.

Escalating political and ethnic violence has raised fears of a return to all-out war in eastern Congo.

The remote region, a stronghold of militias and both foreign and local rebels, has been a tinderbox for conflict since neighbours Rwanda and Uganda invaded in 1998, sparking a 5-year war that aid agencies say killed 3.8 million people.

Refugees often cross borders to flee fighting but many return after a few days.

"With the prevailing insecurity in eastern DRC, such back and forth movements are likely to continue," the UNHCR said, adding that it was organising shelter.

The World Food Programme said it was ready to send some basic food supplies to eastern Congo by helicopter because road access was now impossible and food stocks were low.

MALNUTRITION

WFP spokeswoman Christiane Berthiaume said the malnutrition rate was currently at 17 percent, above the "crisis level" of 15 percent. The agency estimates 200,000 people have been displaced by violence in eastern Congo this year.

UNHCR spokesman Ron Redmond told reporters in Geneva the U.N. agency was concerned that hundreds of thousands of people could be uprooted if fighting continues. He urged both sides to refrain from attacks on civilians.

"We hope that the current problems in North Kivu can still be resolved through negotiations," he said.

Also threatened by the fighting are rare mountain gorillas in Africa's oldest national park, Virunga.

Conservationists said Nkunda's fighters forced out rangers from the Virunga park on Monday, seizing weapons and leaving the gorillas unprotected. Park authorities said fighting broke out on Tuesday when government forces tried to dislodge the rebels.

"The fate of the mountain gorillas now lies in the hands of Nkunda," said Robert Muir of the Frankfurt Zoological Society, which supports the management of Virunga.

"Each day that passes while these troops occupy their habitat puts the survival of the mountain gorillas at risk," he told Reuters from Goma, in eastern Congo.

Nine gorillas have been killed in Congo since the beginning of the year, including two slain and eaten by Nkunda loyalists.

Nkunda launched a rebellion in 2004. Thousands of his fighters were brought into special mixed brigades within the army as part of a January truce, but violence has continued.

Both sides accuse each other of starting the latest clashes.

(additional reporting by Laura MacInnis in Geneva)

AlertNet news is provided by