The Huthis' Al-Masirah TV said four children were among those killed late Monday in coalition air strikes on a vehicle in the rebel stronghold of Saada.

Medical sources separately confirmed to AFP that four children had died.

Releasing a video of the raid, the coalition rejected the allegation as "false and unfounded", insisting that it targeted armed Huthi combatants.

"The video highlights the reality and circumstances of the targeting," a coalition statement said.

"A group of Huthi armed militants are shown carrying weapons in a military logistics operation, within the area of operations in close proximity to the Saudi-Yemeni border."

The incident occurred as the war-ravaged country, already reeling from what the UN calls the world's worst humanitarian crisis, grapples with the fast-spreading coronavirus pandemic.

It comes on the heels of UN chief Antonio Guterres's decision to remove the Saudi-led coalition from a list of groups violating children's rights.

The UN's newly published annual report on children in conflict zones said the toll had fallen since an agreement signed in March 2019.

Both the coalition and the rebels have been accused by the UN and rights groups of committing violations in Yemen that could amount to war crimes.

International aid organisations, including Oxfam, Save the Children and the Norwegian Refugee Council (NRC), have condemned the latest air strikes.

"We share our deepest condolences with the bereaved families and loved ones of those who have lost their lives in this terrible, unjustified attack," said Lise Grande, the UN humanitarian coordinator for Yemen.

"Yemen is desperate for peace. Humanitarian agencies are running out of money and COVID is spreading."

Mohamed Abdi, NRC's country director, said "an investigation must take place, and warring parties responsible for their deaths must be held accountable".

The strikes come after the coalition claimed it has recently intercepted a number of Huthi ballistic missiles and drones targeting Saudi cities near the Yemeni border.

The coalition intervened in Yemen in 2015, shortly after the Huthis seized the capital Sanaa. Tens of thousands of people, many of them civilians, have since been killed.