Yemenis dig graves on August 10, 2018, for children killed in an air strike on their bus in northern Yemen

Dahyan (Yemen) (AFP) - The UN Security Council prepared Friday to discuss an air strike by a Saudi-led coalition that killed at least 29 children, whose remains and clothing were left strewn across a market in northern Yemen.

The coalition itself, following calls from the UN and United States, announced an investigation into Thursday’s strike.

The raid that hit the bus in Dahyan market in the Huthi rebel stronghold of Saada also injured at least 48 others, including 30 children, according to the International Committee for the Red Cross.

An AFP photographer at the shocking scene said the bus transporting the children had been turned into a mass of twisted metal, and that the remains of victims and personal items were still scattered across the ground.

“There are remains everywhere, we are still trying to confirm identies,” Yahya Shayem, a health official in Saada, northern Yemen, told AFP.

The coalition, which has been fighting Yemen’s rebels since 2015, claimed the bus was carrying “Huthi combatants”.

It initially said the coalition had carried out a “legitimate military action”, targeting a bus in response to a deadly missile attack on Saudi Arabia on Wednesday by Huthi rebels.

At a press conference in Dahyan on Friday, Huthi health minister Taha al-Mutawakel put the death toll from the “horrible crime” at 51 people, including 40 children.

“This toll is not final… a lot of people are missing and the remains are still scattered around the crime scene and nearby,” he said.

The Red Cross could not immediately confirm the new figures.

- Children ‘excited’ for trip -

A Yemeni child awaits treatment at a hospital after he was wounded in an air strike in the northern province of Ssaada on August 9, 2018

At the time of the attack, the children were on a bus heading back to school “from a picnic”, the Save the Children charity said, quoting its staff.

One of the children’s teachers told AFP the pupils had eagerly awaited the journey.

“The mothers told me that their children did not sleep for two days because they are were too excited to take part in this trip,” said Yahya Hussein.

The Huthis’ Islamic affairs ministry said the children were from a Koranic school.

The strike prompted UN Secretary-General Antonio Guterres to call for an “independent and prompt” probe.

And the US State Department urged the coalition to conduct a “thorough and transparent” investigation, spokeswoman Heather Nauert said.

In comments Friday on Twitter, the rebels’ revolutionary council head, Mohammed Ali al-Huthi, said his side was “willing to cooperate” in a probe.

In the wake of international criticism, the coalition announced Friday it would open an investigation.

The decision followed details on “a passenger bus which suffered collateral damage in this operation”, a senior coalition official said, quoted by the state-run Saudi Press Agency.

The Security Council was set to meet behind closed doors on Friday to discuss the attack, at the request of five countries which are non-permanent council members.

- Rebel missile attacks -

A Yemeni child stands next to the destroyed bus at the site of a Saudi-led coalition air strike, on August 10, 2018

The coalition, which also includes the United Arab Emirates, intervened in 2015 to try to restore the internationally recognised government after the rebels drove it out of the capital Sanaa.

Coalition spokesman Turki al-Maliki on Thursday said claims by aid organisations that children were inside the bus were “misleading”, and that “the elements inside the bus were Huthi combatants”.

He said the rebels have “ballistic missiles” which threaten Saudi security and described Thursday’s attack as “a follow-up process to neutralise that threat”.

Earlier, Maliki accused the Huthis of “recruiting child soldiers, throwing them in battlefields and using them as tools”.

Saudi Arabia shot down a missile fired by the Huthis on Wednesday, with debris killing a Yemeni man and wounding 11 others, the coalition said.

The missile was fired from the rebel-held Yemeni province of Amran towards the Saudi city of Jizan, the coalition said.

The Huthis have in recent months ramped up missile attacks against Saudi Arabia, which Riyadh usually says it intercepts.

On August 2, attacks on a hospital and a fish market in the strategic rebel-held port city of Hodeida killed at least 55 civilians and wounded 170, according to the ICRC.

The coalition denied responsibility for those attacks.

The war in impoverished Yemen has left nearly 10,000 people dead and unleashed what the UN describes as the world’s worst humanitarian crisis.

The United Nations envoy to Yemen, Martin Griffiths, last week told the Security Council “a political solution” to Yemen’s war was “available” and that the warring sides would be invited to talks on September 6 in Geneva.

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.