Dozens of Yemeni civilians, most of them children, were killed Thursday when an airstrike by U.S.-backed Saudi Arabian forces hit a bus in the rebel-held city of Dahyan, according to sources from the International Red Cross cited by The Guardian. The International Committee of the Red Cross wrote on Twitter that their medical team received 29 dead, all of whom were under the age of 15. They also claim to have received 48 injured from the attack, including 30 children. The Guardian notes that the death toll has not been officially confirmed, but a source told Reuters that 43 people were dead and 61 were wounded. The Red Cross’ Yemen branch took to Twitter to decry the violence, noting, “Under international humanitarian law, civilians must be protected during conflict.” The Saudi government, however, denied the attack violated international law, calling it a “legitimate” targeting of “elements” responsible for a Wednesday attack on the city of Jizan. The kingdom also accused rebel Houthi forces, who the Saudis view as proxies for Iran, of using the children as human shields. More than 10,000 people have been killed during the three-year conflict, which has left millions of Yemenis on the brink of starvation as Saudi forces have imposed a strict blockade on key ports for food.