IBB, Yemen — An airstrike from the Saudi-led coalition struck a school bus in northern Yemen on Thursday and killed dozens of people, many of them children, local medical officials and international aid groups said.
The attack sent a flood of victims to overwhelmed hospitals struggling to cope in what the United Nations considers one of the world’s worst humanitarian crises.
The coalition said it had hit missile launchers and called the attack a “legitimate military operation,’’ but the attack and the justification for it were condemned and drew new attention to the tremendous human toll of the war in Yemen, especially on children.
“No excuses anymore!’’ Geert Cappelaere, UNICEF’s regional director in the Middle East and North Africa, said on Twitter. “Does the world really need more innocent children’s lives to stop the cruel war on children in Yemen?’’
The attack, in a busy market area, hit a bus carrying students on a recreational trip with a Quran memorization program. It killed at least 43 people and wounded 63, according to Muhammad Hajar, an official in charge of emergency services for the Health Ministry. He said the final toll could be higher because rescue operations were ongoing.
The International Committee of the Red Cross said at least 29 of those killed were children under the age of 15, and that 48 people were wounded, including 30 children.
Colonel Turki al-Malki, a spokesman for the Saudi-led coalition, said the attack targeted the rebels who had fired a missile at the kingdom’s south, killing one person and wounding 11 others. The coalition said Wednesday’s projectile, fired toward the southwestern Saudi city of Jizan, was intercepted and destroyed but its fragments caused the casualties.
Malki insisted Thursday’s attack carried out in Saada is a ‘‘legitimate military action’’ and is ‘‘in accordance with international humanitarian law and customs.’’ He also accused the Houthis of recruiting children and using them in the battlefields to cover for their actions.
State Department spokeswoman Heather Nauert said US officials can’t confirm all the details about the attack, but are concerned about reports of civilian deaths.
‘‘We call on the Saudi-led coalition to conduct a thorough and transparent investigation into the incident,’’ Nauert said. ‘‘We take all credible accounts of civilian casualties very seriously.’’
Saudi Arabia backs Yemen’s internationally recognized government and has been at war with the Houthis since March 2015. The rebels control much of northern Yemen, including the capital, Sana.
Saudi Arabia considers the Houthis a proxy force for Iran.
The attack Thursday took place in Sada province, the Houthis’ ancestral homeland, which the Saudi-led coalition has bombed heavily since the start of the war, reducing much of it to rubble. It is also the area from which Houthi fighters frequently launch attacks on Saudi Arabia.
“Under international humanitarian law, civilians must be protected during conflict,’’ the Red Cross said on Twitter.
The head of the group’s delegation in Yemen, Johannes Bruwer, said it had sent supplies to the area to help hospitals.
Material from the Associated Press was used in this report.