Based on interviews, satellite imagery, aircraft observation logs and intercepted aircraft radio communication, Amnesty International has documented unlawful attacks on hospitals and schools in Idlib and western Aleppo governorates by Syrian and Russian government forces, as well as the resulting humanitarian crisis. The research also shows that Hay’at Tahrir al-Sham, the largest coalition of armed groups in the north-west, interfered in humanitarian organizations’ work. Civilians are at further risk if a crucial UN mechanism to deliver humanitarian relief from across the border with Turkey is not renewed. The UN Security Council must ensure this mechanism remains intact.