The first UN aid convoy to reach the heart of rebel-held territory in the war-torn east of Congo arrived yesterday to find refugee camps that had housed tens of thousands of people last week now standing empty.

Stunned aid workers described the camps around Rutshuru that had been sheltering as many as 50,000 people displaced by Eastern Congo's relentless fighting, levelled with all signs of building materials and people gone.

“All the camps are empty. They have all left,” said Francis Nakwafio Kasai, a field officer with the UN Office for the Coordination of Humanitarian Affairs (OCHA). “All the shelters have been destroyed... nothing remains.”

The convoy crossed the front line dividing government forces from the rebel army of Laurent Nkunda unchecked yesterday as the ceasefire declared by the renegade general continued to hold. General Nkunda, a Tutsi and formerly an officer in the Congolese army, advanced to within eight miles of Goma, the largest city in the region, last week before halting his fighters.

The general, who is wanted for war crimes by the Congolese government, is widely believed to have the backing of Rwanda's President Paul Kagame with whom he fought in the wars that followed the 1994 genocide in the small mountainous state. The backwash from that orgy of killing has seen rebel groups of Tutsis and the Hutus, who had slaughtered them during the genocide, contest territory inside eastern Congo, which the chaotic and ineffective Congolese army has not prevented.

The frontline has visited a humanitarian crisis on the civilian population, which could now turn into a “catastrophe,” according to aid groups.

The French Foreign Minister, Bernard Kouchner, who flew to the region for crisis talks with his British counterpart David Miliband at the weekend, said after briefing European Union colleagues on their mission that the UN peacekeeping force in Congo needed to be toughened. Mr Miliband said “no one” had ruled out sending more troops to Congo, but stressed that the UN should continue to take the lead role.

Britain and France have supported opposite sides in the Congolese and Rwandan conflicts.

The Rwandan president did not provide assurances to the two visiting ministers and denied accusations that he was backing General Nkunda.