A boy receives medical attention after surviving an alleged Saudi-led airstrike at a hospital in Sadaa (Image: PA)
The UN Secretary-General, Antonio Guterres, has called for an independent inquiry after an air-strike by the Saudi-led coalition in Yemen is reported to have killed 29 children.
Nearly 50 more people, 30 of them children, were injured in the airstrike at a busy market in Saada province, the International Committee of the Red Cross (ICRC) said.
The UK Government faces calls to cease selling arms and providing military advice to Saudi Arabia, which leads a coalition that carried out the strike.
According to the UN the youngsters had been at a summer camp when the bus was struck on Thursday, with most of the dead between 10 and 13 years old.
The majority of patients being treated at an ICRC-supported hospital were under 10 years old, the campaign group said.
The Saudi-led coalition said it had targeted rebels in the market after they fired a missile at the kingdom on Wednesday, killing one person and wounding 11 others.
If the conflict is left unresolved, Yemen risks becoming "Syria-plus", the British UN envoy to the country has warned
The British UN envoy to the country has warned Yemen risks becoming "Syria-plus" if conflict there is left unresolved.
The ICRC said on Thursday that it had received the bodies of 29 children, all under 15 years old, and there were 48 injured people, among them 30 children, being treated by its medics at a hospital in Saada.
It said on Twitter: "This morning a bus carrying children in Yemen was attacked. Scores of dead and wounded are being treated by our medical teams in Saada the attack in Dahyan Market. The majority of our patients are under 10 years old.
"Our teams are working to save as many people as they can. Causalities from today's attack continue to arrive. We have dispatched medical equipment to another hospital in Saada, to help them cope with the influx of patients."
The Coalition airstrike is the latest to inflict significant civilian casualties in the conflict.
A strike in April was reported to have killed at least 20 people at a wedding, says after at least 20 civilians were reportedly killed in a strike on a bus full of commuters.
In July a report by MPs recommended a new inspection regime should be set up to examine how British arms exports are being used.
The Committees on Arms Export Controls's recommendation was welcomed by the Campaign Against the Arms Trade, which is involved in a legal battle with the Government over the use of British military exports by Saudi Arabia in Yemen.