The Office for the Coordination of Humanitarian Affairs did not specify the type of strikes Saturday in the Jabal Ras district, but Yemeni rebels said they were air raids by the coalition fighting alongside the government.
The coalition s spokesman, contacted by AFP, had no immediate comment.
The UN agency said at least 20 more civilians were injured, in what Lisa Grande, the world body s humanitarian coordinator for Yemen, termed “a horrific incident”.
The Norwegian Refugee Council condemned “an unacceptable pattern of attacks on civilian women, men and children by parties to the conflict who profess concern for the interests and welfare of Yemeni people”.
Saudi Arabia and its allies intervened in Yemen in 2015 to support President Abedrabbo Mansour Hadi s government after the Iran-aligned Huthis ousted it from the capital Sanaa and swathes of the country s north.
The coalition has used air power to oust the rebels from much of the country s south, but the Huthis have held onto Sanaa and the key Red Sea port of Hodeida.
Following the collapse of United Nations-backed talks in September, the coalition announced it was relaunching an assault on Hodeida city and its Red Sea port.
The fighting has since eased and the coalition has focused its raids on the city limits and other parts of the surrounding province.
Coalition air strikes last week killed 79 Huthi rebel fighters and seven civilians in Hodeida province.
The coalition has drawn heavy UN criticism for the high civilian death toll from its campaign in Yemen.
Yemen s war has left almost 10,000 people dead, mostly civilians, since the coalition intervened in 2015, and sparked what the UN has labelled the world s worst humanitarian crisis.