"The air strikes targeted a bus full of school students in the middle of Dahyan market in Saada province while they were going to their school", the official said.
"We call on the Saudi-led coalition to conduct a thorough and transparent investigation into the incident", she said. Turki al-Malki said the attack was "a legitimate military action, conducted in conformity with worldwide humanitarian law".
Saudi Arabian spokesman Col.
In a message on Twitter, the International Committee of the Red Cross (ICRC) in Yemen said a hospital it supports had received dozens of casualties.
In another video, which appears to show the immediate aftermath of the strike, several children's bodies lie under a blown-up bus.
The UK and United States has been criticised for providing logistical and military support to the Saudi-led coalition.
"Putting children in harm's way is horrific and deplorable and making them pay such a price is unacceptable", said Hodeib.
Yemeni tribal leaders told the AP the Saudi-led US -backed coalition fighting Shiite Houthi rebels was behind the airstrike.
The Huthis' Al-Masirah TV, quoting the rebel health ministry, reported that 50 people were killed and 77 wounded, "mostly children", though it was not possible to verify that toll.
Federal Bureau of Investigation says ex-Trump campaign chairman hid over 30 offshore accounts
Gates' earlier testimony on Tuesday, meanwhile, centered on how Ukrainian businessmen paid Manafort for his consultancy work. But Kevin Downing, an attorney representing Manafort, got in one final swipe at Gates before his testimony came to an end.
The coalition's spokesperson said the operation sought to target the militants responsible for a missile intercepted over Saudi civilian territory on Wednesday. He said this made the attack a "legitimate military action in accordance with worldwide humanitarian law".
A military coalition led by Saudi Arabia and the United Arab Emirates got involved in Yemen's civil war in 2015. He also accused Houthis of using kids as "tools and covers for their terrorist acts".
It's not the first time the coalition has hit a residential area this month.
It has launched thousands of air strikes in a campaign to restore the internationally recognised government of President Abdrabbuh Mansour Hadi.
Colonel Turki al-Malki, a spokesman for the Saudi-led coalition, said the missile strike was aimed at a "legitimate target".
Col. Al-Maliki affirmed that the leaders and militants responsible for launching ballistic missiles and targeting civilians would be held accountable under the Coalition's efforts to prevent terrorist elements from compromising regional and global security.
The coalition denied responsibility for those attacks.
"It is beyond cruel; innocent children's lives have been lost". "Parties to the conflict and those who have influence over them, including Security Council members, can and should choose to end this catastrophe for the sake of Yemen's children".
UN-brokered negotiations on Yemen broke down in 2016 amid demands for a rebel withdrawal from key cities and power-sharing with the Saudi-backed government.