As many as 400,000 starving children in Yemen are at risk of dying without urgent treatment for malnutrition, a group of United Nations agencies warned on Friday. 

Nearly 2.3 million children under the age of five in the war-torn country are likely to experience acute malnutrition in 2021, according to an analysis published Friday from the UN food agency , UNICEF, the World Food Program (WFP) and the World Health Organization. 

“The increasing number of children going hungry in Yemen should shock us all into action,” UNICEF director Henrietta Fore said in a joint statement. “More children will die with every day that passes without action. Humanitarian organizations need urgent predictable resources and unhindered access to communities on the ground to be able to save lives.”

Yemen is embroiled in a civil war pitting the Houthi rebels against a Saudi-led military coalition that intervened on behalf of the internationally recognized government in 2015. After some six years of war, the United Nations considers Yemen the world’s worst humanitarian crisis.