Houthi rebels say at least 30 people were killed in an air raid near Hodeidah, at least 20 of them children.
The latest civilian casualties come two weeks after an aerial bombardment that destroyed a school bus, killing 40 children.
Saudi Arabia declared the earlier attack an appropriate military strike, but has promised to investigate.
The charity Save the Children has estimated that an average of 140 children have been killed every day since Saudi Arabia and the UAE began their bombing campaign against the Iran-backed Houthi fighters in Yemen.
Al Jazeera’s Alan Fisher reports from neighbouring Djibouti.