The U.N. Security Council on Saturday expressed its “deep concern” over an imminent attack on al-Fashir in Sudan’s North Darfur region by the Rapid Support Forces (RSF).

War erupted  in Sudan one year ago between the Sudanese army and the paramilitary RSF, creating  the world s largest displacement crisis.

Al-Fashir is the last major city in the vast, western Darfur region not under control of the RSF. The RSF and its allies swept through four other Darfur state capitals last year, and were blamed for a campaign of ethnically driven killings against non-Arab groups and other abuses in West Darfur.