Sudan’s military is accused of using chlorine bombs: here’s how they work and what the law says

Persistent allegations of chemical weapons use in the Sudanese civil war have recently been reinforced by new evidence.

US news outlets The New York Times and The Washington Post reported on materials shared by an anonymous Middle Eastern intelligence agency.

The September 2026 articles paint a picture of concerted efforts by officials in the Sudanese Armed Forces to develop chlorine-based military weapons to be used against the Rapid Support Forces, particularly in and around Khartoum.

The city was the stage of a prolonged battle between the army and the paramilitary forces between April 2023 and March 2025.

It was characterised by heavy attacks in civilian neighbourhoods.

The army took control of Khartoum in January 2026 .

We asked Anneleen van der Meer , who specialises in chemical weapons research, to unpack the significance of these latest findings.

How does chlorine work as a chemical weapon? And what happens to people who are exposed to it? Chlorine is a chemical substance with a variety of peaceful applications.

For example, the purification of water to make it suitable for drinking.

It is often stored as a liquefied gas, meaning liquid under pressure.

In this state, it can be transferred to munitions – military and combat equipment – and used as a weapon.

When the munitions are dropped, they rip open, suddenly reducing the pressure that their contents were under.

This causes the liquid to quickly evaporate into gas.

Contact with this gas can cause symptoms ranging from airway irritation to pulmonary oedema, a condition that causes the lungs to flood as chemical burns damage the lung tissue.