Some of the people who fled Khartoum’s 2016 military offensive in the Jebel Marra region of central Darfur; during the offensive the regime deployed chemical weapons, including against civilians. This has been established beyond reasonable doubt by Amnesty International’s report of September 2016: “Scorched Earth, Poisoned Air: The Sudanese government is inflicting unspeakable human suffering on its own people” | https://www.amnesty.org/en/latest/news/2016/09/chemical-weapons-attacks-darfur/