The US lobby group whose video about Joseph Kony went viral last year says it is "cautious" about reports the fugitive Ugandan rebel chief is negotiating with the Central African Republic.
The small African nation insists that President Michel Djotodia is in contact with Kony, even thought Washington has rubbished claims the wanted militia boss is in talks over the fate of the children and women enslaved by his Lord's Resistance Army (LRA).
"We are very encouraged by the consistent reports over the last few months about the progress that is being made to see an end to LRA violence," said Ben Keesey, head of the California-based lobby group Invisible Children.
"Recent reports alleging that various LRA members want to negotiate their surrender are welcomed indications that the group is becoming increasingly weakened and desperate due to the success of the counter-LRA strategy."
But he added: "Any report that Kony may want to negotiate a surrender should automatically be met with caution. None of our local sources have substantiated the claims that there is a direct communication with Kony.
"Additionally, Kony has used and abused the call for peace talks many times... usually at moments when his power is the weakest," he said, in a statement emailed to AFP Friday.
Kony, originally from Uganda, is wanted by the Hague-based International Criminal Court (ICC) for leading a grim campaign of rape, mutilation and murder, kidnapping boys to serve as child soldiers and girls as sex slaves.
The manhunt across Uganda, Democratic Republic of Congo, Central African Republic and South Sudan has been given new impetus by the Kony 2012 campaign and its video, viewed by more than 100 million people.
The co-founder of the online campaign, Jason Russell, suffered a very public breakdown due to what his family said was the pressure and exhaustion of the campaign.
He spent several weeks in hospital after being found -- and filmed in a video which also went online -- parading naked in the street in March last year, screaming at cars and thumping the sidewalk.