SANAA, Yemen — An estimated 85,000 children under age 5 may have died of hunger and disease since the outbreak of Yemen's civil war in 2015, an international aid group said Wednesday.

Save the Children said the "conservative" estimate is based on average mortality rates for Severe Acute Malnutrition, which the U.N. says has afflicted more than 1.3 million children since a Saudi-led coalition went to war with Yemen's Houthi rebels in March 2015.

Tamer Kirolos, Save the Children's Yemen director, says: "For every child killed by bombs and bullets, dozens are starving to death and it's entirely preventable," adding that "children who die in this way suffer immensely."

The war and a Saudi-led blockade have created the world's worst humanitarian crisis, with more than 8 million people at risk of starvation.