Coalition spokesman Maliki confirmed the strike had hit a bus, telling AFP "the elements inside the bus were Huthi combatants".
"We are unable to verify the details at this moment", Save the Children wrote on August 9. He also accused the Houthis of recruiting children and using them in the battlefields to cover for their actions.
"Under worldwide humanitarian law, civilians must be protected during conflict", it added.
Muzahem said he and others carried the victims from the market to cars to transport them to the nearest hospital, but they were anxious they would be hit by more air strikes. "All of those who died were residents, children and shop owners", witness Moussa Abdullah, who was being treated in hospital for wounds, told Reuters.
According to Abu Muzahem there are no military bases or positions near the market. The airstrikes targeted Sabeen Square and two military camps.
"The air strikes often target civilians in Saada, so we appeal the worldwide community to intervene to stop the Saudis killing them".
The Red Cross Yemen branch noted that under worldwide humanitarian law, civilians should be protected during times of war.
The International Committee of the Red Cross said it was sending supplies to ICRC-supported hospitals to support an influx of casualties.
The International Committee of the Red Cross, citing local officials, announced that a total of 50 people have died in the attack and 77 have been injured, majority children.
They also report the hospital took in 40 injured, 30 of them children.
"I am watching with horror the images and videos coming from Saada in #Yemen and I have no words".
"The place is known to be a market, [and] there is no military installation nearby. but the Saudis are known to have done this many times-target schools, weddings and so on", Nasser Arrabyee told Al Jazeera.
It was unclear how many children were killed and how many air strikes were carried out in the area, in northern Yemen, near the border with Saudi Arabia.
Saudi Arabia, the driving force behind a coalition of its Arab neighbors, saw no reason to apologize, however.
There was a horrifying attack Thursday in Yemen - a Middle Eastern country torn apart by a 3-year-old civil war.
"We are calling the Saudi led coalition to conduct a thorough and transparent investigation into the incident", she said.
On Wednesday, a Saudi-led coalition spokesman Col.
The Houthis have fired a number of ballistic missiles at the Saudi capital, Riyadh, and other cities.
UNICEF said in a statement that "many children were reportedly killed and injured" in the attack and that all of the children were reportedly under the age of 15.
In May, the Trump administration imposed sanctions on five Iranians linked with the Islamic Revolutionary Guard Corps (IRGC) who allegedly provided ballistic missile support to the Houthi rebels in Yemen which they then used to attack Saudi Arabia. But the coalition denied carrying out any attacks in the city, saying it follows a "strict and transparent approach based on the rules worldwide law".