More than 200 people in Sudan have allegedly been killed by chemical weapons dropped on them by their own government, it is claimed.
Dozens of children and babies are among those killed by the banned weapons in Darfur since January, Amnesty International said in a new report.
Amnesty International has published an investigation which they sayuncovered "scorched earth, mass rapes, killings and bombs" in Jebel Marra, a remote region of Darfur.
Researchers found 56 witnesses to the alleged use of chemical weapons on at least 30 occasions by Sudanese forces.
Victims affected by the "poisonous smoke" vomit blood, struggle to breathe and watch as their skin falls off.
The Sudanese government has said the allegations are "baseless and fabricated".
Conflict has raged in Darfur between the government in Khartoum and rebels for 13 years.
Satellite imagery confirms that 171 villages have been destroyed or damaged in last eight months, the human rights organisation said.
"The scale and brutality of these attacks is hard to put into words," said Ms Hassan. "The images and videos we have seen in the course of our research are truly shocking; in one a young child is screaming with pain before dying; many photos show young children covered in lesions and blisters. Some were unable to breathe and vomiting blood."
One woman in her twenties was injured by shrapnel when a bomb which emitted a toxic cloud of smoke fell inside her village. She and her baby became sick and six months later they are still suffering from the effects.
"When [the bomb] landed there was some flames and then dark smoke. Immediately it caused vomiting and dizzying. My skin is not normal. I still have headaches, even after I took the medicine. The baby is not recovering, he is swollen, he has blisters and wounds, they said he would get better but it is not working," she said.
A man named Ismail, who tried to help people in late January, told Amnesty: "Their skin was falling off and their bodies had become rotten… and their breath was very bad".
Several of the children he treated died, others were still in pain months later.
Two independent chemical weapons experts agreed the injuries seen were consistent with a chemical attack, with symptoms pointing to vesicant or blister agents.
Amnesty is calling on the UN Security Council to:
Apply political pressure on the Sudan government to ensure that peacekeepers and humanitarian agencies are allowed to access remote communities.
Urgently investigate the use of chemical weapons and, if there is sufficient admissible evidence, prosecute all those suspected of responsibility.
Ensure the current arms embargo is strictly implemented and extended to cover the whole country.
The allegations of use of chemical weapons by Sudanese Armed Forces is baseless and fabricated. The ultimate objective of such wild accusation, is to steer confusion in the ongoing processes aimed at deepening peace and stability and enhancing economic development and social cohesion in Sudan.