At least 29 children were among those killed in the air raid on Thursday on a bus in a crowded market in Dahyan, Saada province, according to the International Committee of the Red Cross.

The mass funeral was held in Saada city, a stronghold of the Iran-backed Huthi rebels, with images broadcast by the rebels' Al-Masirah television.

Around 50 vehicles brought coffins into a large square in the city.

The coffins were covered with green drapes and portraits of the victims were lined up on the ground for the Muslim prayer of the dead.

Mourners shouted slogans against Saudi Arabia and its ally and key arms supplier, the United States. "America kills Yemeni children," read several banners.

The Saudi-led coalition has taken part in Yemen's conflict since 2015 in support of President Abedrabbo Mansour Hadi's government in its fight against the Huthis.

The head of the Huthis' revolutionary council, Mohammed Ali al-Huthi, took part in the funeral and slammed the raid as a "crime by America and its allies against the children of Yemen".

The Huthis' health ministry said that 51 people were killed in the raids including 40 children.

It also said 79 others were wounded, including 56 children.

Al-Masirah did not say how many victims were buried on Monday.

Some families had already buried their loved ones, according to residents.

The coalition said Friday it will launch a probe to "assess the events (and) clarify their circumstances", while the UN Security Council has called for a "credible investigation".

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 UN envoy to Yemen, Martin Griffiths, has invited the warring sides to talks on September 6 in Geneva.