At least 10 people were killed on Wednesday in an air strike that hit a group of farmers in a vegetable market in Yemen's Hodeidah province, medical workers and residents said.
A Saudi-led coalition that intervened in Yemen’s war in 2015 has conducted frequent air strikes targeting the Iran-aligned Houthi group.
Medics and residents in Bayt al-Faqih, a town 70 km (40 miles) south of Hodeidah city, said nine other people were also wounded in the air strike.
Houthi media said 19 were killed and 10 were wounded in the same area.
Residents said violent clashes erupted in the southern outskirts of Hodeidah, a port city that pro-government forces have been trying to capture from the Houthis since the renewal of an offensive in September.
A spokesman for the Saudi-led coalition, Colonel Turki al-Malki, said the alliance is investigating the incident.
"We take this report very seriously and it will be fully investigated, as all reports of this nature are, using an internationally approved, independent process. Whilst this is ongoing, it would be inappropriate to comment further," he said.
The coalition entered Yemen’s conflict after the Houthis ousted the internationally recognised government of President Abd-Rabbu Mansour Hadi.
The war has killed more than 10,000 people, displaced more than 2 million and driven the country, already the poorest on the Arabian Peninsula, to the verge of widespread famine.