Saudi-led coalition air strikes on a marketplace and house in rebel-held northern Yemen have left at least 14 people dead, witnesses and a rebel-run news agency said on Thursday.

An eyewitness in the northern province of Saada told AFP that 12 people had been killed in strikes on the marketplace on Wednesday evening, including women.

The rebel-run news agency Saba gave the same toll and accused the coalition of using cluster bombs in that attack in Kataf city.

In the Baqim district of Saada province, two people were killed in a Saudi-led air strike on a house, another witness said.

Saba gave the same toll and said that separate strikes on a house near the Saudi border had left another two people dead although there was no independent confirmation.

Saada is a stronghold of the Houthis who continue to hold large swathes of territory in the north including the capital Sanaa.

In early November, the coalition tightened a blockade on Yemeni ports and airports in response to a missile fired by the Houthis that was intercepted near Riyadh airport.

The country is facing what the United Nations has described as the world's worst humanitarian crisis.

Saleh commander presumed dead appears in video

A nephew of slain Yemeni strongman Ali Abdullah Saleh, presumed dead or critically wounded in clashes with rebels last month, appeared alive and well in footage that emerged on Thursday.

A video received by AFP showed Tarek Saleh, for years the head of his uncle's forces, addressing a crowd in what a source close to the family said was the southern province of Shabwa, an area controlled by the government against which Ali Abdullah Saleh had fought since 2014.

While the video's authenticity could not be immediately verified, Tarek Saleh appeared to address the killing of his uncle and a senior aide last month.

Speaking to a small crowd of men who had gathered to cheer him on, he offered his condolences over “the martyred leader” — probably a reference to Ali Abdullah Saleh — and “the martyr Aref al-Zouka”.

Zouka, from Shabwa, was secretary general of Saleh's General People's Congress (GPC) which was allied with the Houthi rebels against the government from 2014 until the end of 2017.

GPC member Nabil al-Sufi, a close friend of the Saleh family, said the video was taken after Tarek Saleh arrived in Shabwa.

The commander had been presumed dead after being wounded in the clashes with Houthis last month.

The GPC, which has begun to show signs of cracking since Ali Abdullah Saleh's death, on Sunday elected former deputy premier Sadiq Amin Aburas as its new chief.

Long-time enemies, former president Ali Abdullah Saleh and the Houthis joined ranks in 2014, driving Yemen's Saudi-backed government from the capital and setting up a parallel state.

But simmering tension between Saleh and the Houthis erupted in Sanaa on November 29, with Tarek Saleh's residence one of the first flashpoints in the fighting.

Saudi Arabia leads a military coalition that intervened in Yemen in March 2015 with the stated aim of rolling back Houthi rebel gains and restoring the country's internationally recognised government to power.

More than 9,000 people have been killed in Yemen since then, according to the World Health Organisation.