Despite killing dozens of schoolchildren, the spokesman called Thursday's attack on the school bus a "legitimate military action" and said it is "in accordance with global humanitarian law and customs".
"Scores killed, even more injured, most under the age of 10", Johannes Bruwer, head of the delegation for the ICRC in Yemen, said earlier in a Twitter post.
Sen. Chris Murphy (D-Conn.), an outspoken critic of the United States' support for the Saudi coalition, expressed fury over the attack and demanded once again that lawmakers end their complicity in the war.
The Saudi-led Coalition, which has been conducting a military campaign to oust the Houthi rebels, didn't immediately respond to CNN questions.
"We see violations across the country and it's really sad to speak about civilian casualties in a matter of less than a week".
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.
"Save the Children condemns this horrific attack and is calling for a full, immediate and independent investigation into this and other recent attacks on civilians and civilian infrastructure", it said.
Geert Cappelaere, the UN Children's Fund regional director in the Middle East and North Africa, said all the children on the bus were "reportedly under the age of 15".
The world has forgotten Yemen's bloody war, but when you look at these young victims - their tiny bodies, some still struggling for life - you won't be able to forget them.
A doctor treats children injured by the airstrike.More news: Boris Johnson under mounting pressure to apologize for controversial burqa comments
Houthi media broadcast gruesome footage appearing to show the dead bodies of children.
Air strikes by the Saudi-led coalition have killed hundreds of civilians at hospitals, schools and markets.
He criticized Riyadh for denying Iranian delegates entry visas for OIC summits, saying such statements "are compiled and released unilaterally and unjustly under pressure from Saudi Arabia". "Causalities from today's attack continue to arrive", the Red Cross stated on August 9.
"The coalition will take all necessary measures against the terrorist, criminal acts of the Huthi militia, such as recruiting child soldiers, throwing them in battlefields and using them as tools", coalition spokesman Turki al-Maliki said, referring to Thursday's attack.
On Wednesday night, Col. Al-Maliki stated that at (20:34) the Coalition Air Defense detected a ballistic missile launch from Northern Amran in Yemen, aimed at Saudi Arabia.
A spokesman for the Saudi-led coalition, which is fighting Houthi rebels in Yemen, said it was targeting rebel missile launchers.
Saudi Arabia says this was a legitimate military operation, targeting Yemeni rebels backed by Iran, its arch enemy.
The coalition said Wednesday's attack brought the tally of rebel missiles launched since 2015, the year it joined the Yemeni government's fight against the rebels, to 165.
The International Committee of the Red Cross (ICRC) said a hospital it supported in Saada had received dozens of casualties on Thursday after the attack.