Medical sources told Reuters the civilians died when the air strikes hit a Houthi checkpoint in the town of Jabal Rass while a bus was passing through.
Eight members of the same family were among the victims, they said.
The Houthi movement’s Al Massira TV said 17 died and many others were in a critical condition.
A spokesman for the Saudi-led coalition could not immediately be reached for comment.
The coalition intervened in Yemen’s war in 2015 to restore the internationally-recognized government to power. It has conducted thousands of air strikes targeting the Iran-aligned Houthis, and has often hit civilians, but denies doing so intentionally.
The war has killed more than 10,000 people, displaced more than two million and driven the country - which was already the poorest on the Arabian Peninsula - to the verge of widespread famine.