Now you see them, now you don't. The Janjaweed in Darfur are becoming invisible.

They are accused of committing some of the most vicious attacks on civilians seen in northeast Africa, with backing from the Sudanese government. Lurking in the dusty towns and sandy plains of Darfur, they wait to carry out the next raid, the next deadly assault on villagers across the region.

But now it seems they are changing their ways. Not their reprehensible actions in slaughtering civilians, but the way they look.

"I see Janjaweed in and out of town, but they are changing," said Terab, a doctor in southern Darfur who has treated both Janjaweed and victims of their attacks on black villagers.

"They don't wear the clothes they used to wear. They have been given new brown and green uniforms that make them look like army soldiers. Some even have berets. But they are not soldiers. They are Janjaweed and that means they are very dangerous, violent men.

"Now they sit around on the back of trucks with guns mounted on the back, looking like they are doing official business. All the locals know who they are because many of them have either been attacked, had family members attacked or friends attacked or even killed by the Janjaweed. The change has really become noticeable over the last couple of weeks."

The danger is that if Janjaweed are no longer identifiable to outsiders, it makes dealing with them impossible.

"They have always been obvious in their appearance," said Abdulman, a local in the southern town of Kass. "They wear old clothes, sometimes camouflage jackets or shirts, sometimes robes. When (Sudanese President) Omar al-Bashir visited Darfur last year they were everywhere and they really stuck out."

Not any more. A local source told me he personally recognised Janjaweed sitting in among the army soldiers seen in this photo.

The Janjaweed's attacks have become notorious for their cruelty, earning the militia the reputation of "devils on horseback".

Over the last four years they have terrorised civilians, forcing hundreds of thousands of people to flee for refuge in the vast camps across the region. To date the U.N. believes 2.5 million people have been displaced in Darfur.

Extensive eyewitness accounts and U.N. reports say the Janjaweed are guilty of carrying out a sickening campaign of rape against women and young girls, using brutal sexual assault as a tool of war to strike fear into the people of Darfur.

They have torched entire villages, burning not just homes but crops and also killing or stealing livestock.

But perhaps their most despicable crime to date is the slaughter of tens if not hundreds of thousands of civilians in what many here believe is an attempt to ethnically cleanse Darfur of it's black African population - a charge supported by the U.S. government's description of the atrocities in the region and "genocide".

Last year, the U.N. estimated that up to 200,000 people had been killed since the start of the conflict. Other organisations say the figure is closer to 400,000. What is agreed is that the Janjaweed has played a leading role in the massacres.

Some of the methods of killing have included throwing people, including young children and babies, on top of burning homes, or brutal beatings with clubs and cutlasses where the victim is left to die alone and unaided.

One child brought into a clinic near Kass was so badly burned that medics at the clinic where initially unable to determine the child's gender.

With tensions already high here and animosity growing ever stronger towards the government, there is growing speculation that the Janjaweed is being supplied with uniforms by the government. And although Khartoum has vehemently denied any connection to the Janjaweed throughout the conflict, Darfuris in general think otherwise.

"Everybody here knows the government have been giving the Janjaweed money and supplying them with arms," one Sudanese aid worker near El-Fasher told me.

"It is no surprise to us they are now giving the Janjaweed uniforms. They might as well do so as there is no difference between the army and the Janjaweed. Both attack civilians and both support and are supported by the government."

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