A suspected raid by the Saudi-led coalition intervening in Yemen killed 23 civilians on Wednesday, including women and children, near the southwestern city of Taez, Houthi rebels said.
A military source with loyalist forces confirmed the raid, saying 20 civilians had died, and said it appeared to have been the result of a "mistake".
Saba news agency, which is controlled by the Iran-backed rebels, said a vehicle carrying civilians in the town of Mawzaa, southwest of Taez, was hit in the raid.
Six children were killed, said the agency, adding that six other people also died in the attack but their bodies were burned beyond recognition.
The military source said the air strike targeted an area held by the Houthi rebels, and also confirmed that a vehicle had been struck.
The passengers were heading back to Mawzaa after a shopping trip to the nearby town of Barah, the military source said, adding several bodies had been torn to pieces.
There was no immediate reaction from the Saudi-led coalition, which has been battling the Houthis opposed to the government of President Abedrabbo Mansour Hadi.
The raid comes days before US President Donald Trump is to arrive on Saturday in Saudi Arabia on his first foreign trip since taking office in January.
The Saudi-led coalition, which intervened on the side of the Hadi government two years ago, has come under repeated criticism over civilian casualties in Yemen.
Yemen's conflict has killed more than 8,000 people and wounded around 40,000, according to the UN's World Health Organisation.