A spokesman for the Saudi-led military coalition says that major combat operations in Yemen are coming to an end, a year after the start of the alliance's intervention.

Brigadier General Ahmed al-Asiri told AP news agency on Thursday that the coalition would work on "long-term" plans to bring stability to the country.

He added that the alliance would continue to provide air support to Yemeni forces battling Houthi rebels on the ground.

The year-long air campaign and ground assault was intended to roll back the Shia rebels, who seized the capital, Sanaa, in 2014 and still control it.

Al-Asiri's announcement came just a few days after forces loyal to Yemen's Saudi-backed President Abed Rabbo Mansour Hadi claimed to have recaptured the western entrance to the city of Taiz.

The Iranian-backed Houthi rebels took control of Taiz nearly a year ago.

Al-Asiri said the coalition was investigating reports of mass killings in northern Yemen after two Saudi-led air strikes hit a market on Tuesday.

The Houthi-controlled state news agency, SABA, said at least 65 people were killed and 55 wounded.

The spokesman for UN Secretary-General Ban Ki-Moon, Stephane Dujarric, said in a statement that the latest attack underscored the need for all sides to respect human rights laws amid the fighting.

"Attacks directed against civilians and civilian objects, including populated markets, are strictly prohibited," he said.

The fighting has killed more than 6,200 civilians and displaced millions, pushing the Arab world's poorest country to the brink of famine.