Dozens are dead and wounded after an airstrike hit a bus carrying children in northern Yemen Thursday, according to the International Committee for the Red Cross and eyewitnesses.

The school bus was hit as it was driving through a market in the rebel-held province of Saada, according to the Houthi-run Al-Masirah TV.

"Scores killed, even more injured, most under the age of ten. @ICRC_ye sending additional supplies to hospitals to cope with the influx," Johannes Bruwer, the head of the ICRC delegation in Yemen wrote on Twitter.

The Saudi-led Coalition, which has been conducting a military campaign to oust the Houthi rebels, didn't immediately respond to CNN questions.

Houthi media broadcast gruesome footage appearing to show the dead bodies of children. Other footage showed a young boy carrying a UNICEF backpacks being escorted to a hospital, his face bloodied as medical staff tried to treat his injuries.

Witnesses that CNN spoke to said the attack could be heard from neighboring districts.

Yahya Shaem, head of the Houthi-held health office in Saada, told CNN that the children in the bus were on their way to their summer camps.