At least 38 people were killed in Saudi-led air strikes on rebel-held security buildings in Yemen's west, including a detention centre, an official said on Sunday.

The provincial official told AFP the bodies of 38 people were transported to hospitals in the port city of Hodeidah, which the Shia Houthi rebels and their allies have held since late 2014.

The official, speaking on condition of anonymity, did not specify the number of prisoners who died in Saturday's raids.

Most of the more than 40 inmates at the facility were opponents of the Iran-backed Houthi rebels, according to a military source close to the insurgents.

Previously, medical and military sources had said the number of inmates and insurgents killed in the air raids on the buildings in Zaidia, north of Hodeidah, was more than 30.

Elsewhere on Saturday, strikes on residential buildings killed 17 people and wounded seven in the battleground town of Salo, southeast of Yemen's third city Taez, said rebel-controlled media.

The sabanews.net website said four raids had completely destroyed three residential buildings.

The Saudi-led coalition has yet to comment on the report, but a local official loyal to Yemen's internationally recognised government said its air strikes had hit three adjacent homes by mistake.

"All those in the houses were killed," he told AFP, adding a child and seven women were among the dead.

Forces loyal to President Abedrabbo Mansour Hadi's government have been locked in deadly battles with Iran-backed Shia Houthi rebels who overran the capital Sanaa in 2014.

The conflict escalated in March last year when Saudi Arabia launched a military campaign to push back the rebels.

The conflict has killed nearly 7,000 people, mostly civilians, according to the United Nations which had been struggling to convince the warring parties to implement a ceasefire and revive a stalled political process.