By Joe Bavier
MASISI, Congo, Sept 5 (Reuters) - Their faces expressionless, Tutsi rebels carrying machine guns brace against a cold wind-whipped drizzle on a muddy track in the green pastureland of Congo's eastern highlands.
Just a few hundred metres (yards) back down the hillside, Congolese government soldiers occupy positions.
Beyond the rebel checkpoint lies the personal fiefdom of renegade Tutsi General Laurent Nkunda, whose feud with the government in Kinshasa is once again turning the east of Democratic Republic of Congo into a war zone.
In two weeks of fighting that worsened sharply in recent days, Nkunda's fighters have battled with the United Nations-backed Congolese army in North Kivu province, forcing thousands of civilian refugees over the border into Uganda.
While U.N. aircraft ferry government forces and supplies to the front line, Congolese commanders say they are using a Russian-built helicopter gunship to pound Nkunda's position.
They say they have killed more than 100 rebel fighters, but there has been no independent verification of casualties.
Analysts believe Congo's President Joseph Kabila may be trying to annihilate Nkunda militarily, anxious to pacify the vast, mineral-rich former Belgian colony after his victory in landmark elections late last year.
But the roots of Nkunda's rebellion lie in unhealed ethnic and political wounds that make the racially-mixed eastern Congo a regional tinderbox. The presence of both Tutsi and Hutu rebels there stems from Rwanda's 1994 genocide and subsequent invasions by Rwandan forces that helped ignite a 1998-2003 war in Congo.
"At the moment, there's been no public political mechanism launched by Kinshasa to start negotiations. And in their absence, the army seems to have clear orders to pursue a military option that could easily lead to an escalation," Jason Stearns, an independent central Africa expert, told Reuters.
Rwandan Foreign Minister Charles Murigande visited Kinshasa for the first time in three years this week as part of efforts to solve the conflict, but his talks appeared to produce few concrete results.
STALLED DEMOBILISATION
The fighting shattered a January truce under which Nkunda's Tutsi fighters were being integrated into the national army.
But the eight months during which many of his men joined mixed Congolese army brigades have allowed Nkunda to consolidate his position in North Kivu and some observers say he holds sway over a third of the province -- an area equivalent to two-thirds of neighbouring Rwanda.
This could make it more difficult for Kabila's poorly-equipped and badly paid army to crush him.
"Nkunda has emerged stronger than before. He's benefited from government salaries for his fighters, and he's been able to deploy throughout the province in strategic locations he was never able to occupy before," Stearns said.
Integrating former rebels is part of an internationally backed demobilisation plan which is seen as key to achieving a lasting peace in Congo, where the world's biggest U.N. peacekeeping force -- 17,000-strong -- is still deployed.
But Nkunda, who says he commands 8,000 fighters, says the reasons which drove him to lead a 2004 revolt in defence of his Congolese Tutsi people have not gone away.
"When there is rebellion in a country, it's because there are problems. And if those problems are not resolved, the rebellion will continue," he told Reuters in a recent interview.
Nkunda accuses Kabila's government and army of supporting rival rebels of the largely Hutu Democratic Forces for the Liberation of Rwanda (FDLR) who control parts of North Kivu.
This is made up of former Rwandan soldiers and members of the Hutu militias, or Interahamwe, which took part in Rwanda's 1994 genocide in which more than 800,000 people were killed.
AFTER EFFECTS OF GENOCIDE
"We're still seeing the after effects and tremors of the genocide. The problem is we have a heavily armed minority (in Congo), that feels threatened, and have big brothers across the border," said Anneke Van Woudenberg, a Congo researcher for New York-based Human Rights Watch.
As part of a 2002 accord with Kigali that led to a withdrawal of Rwandan troops from Congo, Kinshasa promised to disarm and repatriate the FDLR Hutu fighters.
Rwanda resumed diplomatic ties with Congo last year in apparent recognition that Kinshasa had made some efforts to rein in the FDLR. Foreign Minister Murigande said this week Rwanda wanted to upgrade relations to ambassadorial level.
But Nkunda remains defiant.
"We will continue to fight for our freedom. We cannot allow North Kivu and South Kivu to be controlled by the FDLR."
