Hundreds of refugees in Darfur are being forcibly evicted from a camp by Sudanese soldiers and police, a UN official has told the BBC.
More than two million people have fled since the conflict began
Men and women were loaded at gunpoint onto trucks at a camp in Nyala, the capital of south Darfur, said the official, who asked not to be named.
The UN tried to intervene in the operation, which it described as illegal, but were prevented.
Sudanese officials said the refugees were being taken to a safer camp.
The refugees were guarded by troops, police and Sudanese national security personnel, the UN official said.
Armed with machine guns, sticks and rubber hoses, they packed around 50 refugees and their belongings onto each truck, as evening fell.
The Sudanese officials told the UN the camp at which they had been living was dangerous, following tribal clashes.
While the UN official said there was some truth to this, the forced relocation was illegal and dangerous to carry out at night.
The governor of South Darfur has told the UN it is his intention to close the camps around Nyala, which are home to as many as 90,000 people.
According to a British charity, the Aegis Trust, this kind of camp closure has been on the cards since June, when President Omar al-Bashir said he wanted to close what he called "these museums of despair".
Human rights groups fear forced relocation would open the way for ethnic cleansing.
"This could be the start of a long-term plan, to change the demographics of the region, under the noses, and in the presence of the United Nations, that won't be able to do anything about it," says Dr James Smith of the Aegis Trust.
"It can get away with this kind of population movement, this illegal population movement, without firing a shot."
The fighting in Darfur has driven over two million people from their homes.
The camps for the displaced have never been entirely secure, but under the eyes of the UN they have offered some sanctuary from attack.
That may now be about to change.