Saudi-led air strikes killed 41 civilians and wounded 75 on Tuesday in Yemen's northwestern province of Haja, a senior provincial health official said, a region largely controlled by the Iran-allied Houthi militia.

A spokesman for the Saudi-led coalition that intervened in Yemen's civil war was not immediately available for comment.

The coalition entered the conflict a year ago to stop Houthi forces and others loyal to ex-president Ali Abdullah Saleh from seizing the entire country, and has fought to restore the government of President Abd-Rabbu Mansour Hadi.

Three of Tuesday's air raids hit an outdoor market in the Mustaba district, Ayman Mathkour, director of the Haja health department, told Reuters. He said relatives gathered the bodies and took the wounded to Abs and Mustaba hospitals.

Saba Net, a Yemeni news agency controlled by the Houthis, reported that 65 people had been killed and 55 wounded in the strike on a market and restaurant in Mustaba. A spokesman for the coalition was not immediately available for comment.

The global charity Medicins Sans Frontieres (MSF) said earlier on Tuesday that more than 40 people, all of them civilians including an eight-year-old in critical condition, were admitted to Abs Hospital after an air strike in Mustaba.

Over 6,000 people, half of them civilians, have been killed in Yemen's conflict since the Saudi-led intervention began in March 2015, according to the UN.

In January, a UN panel found that air strikes had targeted civilians, assessed that some of the attacks could be crimes against humanity and recommended the UN Security Council consider establishing an investigation.

The Saudi-led coalition strongly denies targeting civilians. In January it said it had introduced tougher procedures to investigate reports of strikes that caused civilian deaths and to improve its targeting mechanisms with US help.