Ugandan rebel movement the Lord's Resistance Army, now based in the far north of the Democratic Republic of Congo, is continuing its attacks on civilians in DR Congo and southern Sudan, despite a three-month campaign to hunt the rebels down.
The BBC's Africa analyst, Martin Plaut, looks at how the LRA has survived and considers who might be re-supplying it.
On 14 December last year Ugandan aircraft attacked camps of the LRA in the remote Garamba National Park, in the north-east of the DR Congo.
The operation against the LRA - known as Lightning Thunder - was launched by Uganda, DR Congo and Sudan.
But despite fierce engagements, the rebels have not been defeated and are continuing a series of murderous attacks on civilians.
Around 100,000 Congolese and 60,000 southern Sudanese have been driven from their homes.
Scattered across a vast area of northern Congo and southern Sudan, the continued operations of the Lord's Resistance Army and their leader, Joseph Kony, are perhaps not surprising.
This is an area of dense forests and swamps - ideal territory for rebel attacks.
But what is less easy to understand is how the LRA manages to co-ordinate its ambushes when its forces are so dispersed.
Where do they get the satellite phones they use - as well as the ammunition, food and medicines their forces require?
Over the last week there have been a growing number of reports that the LRA has been re-supplied from the air.
Late last month there was an attack on the village of Banda, which forced locals to evacuate the area.
This - according to the reports - was designed to clear the area for an air-drop to take place.
There is also the testimony from LRA abductees who managed to escape from the rebels.
They say that air-drops took place in a mountainous area called Karago, west of the town of Aba.
The United Nations mission in Congo, Monuc, says it has heard the rumours, but has no evidence that the air-drops are taking place.
"Our military seem sceptical that the reports are true, given the level of co-ordination that would be required on the ground," Monuc spokesman Madnodje Mounoubai told the BBC.
"But the fact is that we just don't know and often lack reliable, timely, actionable intelligence," he said.
Although there is no confirmation of these reports, they have come from several sources.
So where might the flights have originated?
Southern Sudanese officials have said openly that they believe that Khartoum continues to support the LRA.
The accusation has been denied by the LRA spokesman, David Matsanga, who told the BBC Focus on Africa programme that the suggestion is designed to frustrate attempts to re-launch the peace process.
"The Ugandan government is looking for ways of finishing the situation militarily, because they don't want to talk about what has happened," said Mr Matsanga.
"These accusations are coming now to inflame the situation," he added.
The Sudanese government has routinely denied that it is re-supplying the LRA, but the question remains - how are the rebels managing to continue their operations if they have no outside backer?