Save the Children, an international aid group, has calculated approximately 85,000 children under the age of 5 have starved to death as a result of civil war in Yemen. The group says the number is a “conservative estimate” based on historical studies of severe acute malnutrition (SAM) in children. The United Nations estimates around 1.3 million children have suffered from SAM in the wake of a war between Yemen’s rebel faction and a Saudi-led coalition which began in 2015.

“For every child killed by bombs and bullets, dozens are starving to death and it’s entirely preventable,” Tamer Kirolos, Save the Children’s Yemen director, told the AP. “Children who die in this way suffer immensely as their vital organ functions slow down and eventually stop.”

The huge death toll is just part of what experts are calling the world’s chief humanitarian crisis, which has left approximately three-quarters of Yemen’s population in need of life-saving assistance.

Save the Children attributed the lack of food to a Saudi blockade that has tightened over the last year, as well as increased infighting around the city of Hodeida, a port city that imports about 70 percent of the nation’s food and aid.

The fallout of the murder of journalist Jamal Khashoggi has renewed the world’s interest in the conflict. U.N. envoy Martin Griffiths says that both sides have agreed to peace talks “soon.”