The Sudanese army has used chemical weapons at least twice against RSF, four senior US officials said on Thursday.

The weapons were recently deployed in remote areas of Sudan and targeted members of the paramilitary Rapid Support Forces (RSF), which the army has been fighting since April 2023. But U.S. officials are concerned that the weapons could soon be used in densely populated parts of the capital Khartoum.

The revelation of chemical weapons use comes as the United States is expected to announce sanctions against Sudan’s army chief, General Abdel Fattah al-Burhan, for documented atrocities committed by his forces, including the indiscriminate shelling of civilians and the use of starvation as a weapon of war.

The use of chemical weapons goes further in the war between the Sudanese army and the RSF. According to many statistics, the war has created the world’s worst humanitarian crisis, with up to 150,000 people killed, more than 11 million displaced, and now the world’s worst famine in decades.

The United Nations, allied countries and aid organizations were notified on Wednesday evening of the impending sanctions against Lieutenant General Burhan. The U.S. decision is a significant move against a figure seen by some as Sudan’s head of state who also represents his country at the United Nations.

Aid groups fear that the Sudanese military may retaliate against the sanctions decision by imposing further restrictions on relief operations in areas suffering or slipping into famine.

It was not immediately clear what type of chemical weapons were used. Two U.S. officials, speaking on condition of anonymity to discuss sensitive security matters, said knowledge of the chemical weapons program was limited to a small group within the Sudanese military. But they said it was clear that General al-Burhan had authorized their use.

New York Times: Declan Walsh – Julian Barnes