Yemen Houthi missile attack kills 15 soldiers, three children
Pro-government forces were stationed in the school having captured Kadha district from Houthi forces last week, according to military sources and residents.
Local residents identified the children as being two brothers and their relative, according to Reuters.
Clashes have escalated in recent weeks between pro-government forces and the Houthis, who ousted Yemen's internationally-recognised government from Yemen's capital, Sanaa, in 2014.
Houthi spokesman Yahya Sarea said three drones had struck the Abha airport and the King Khalid air base in the southern town of Khamis Mushait, according to Reuters.
The coalition Saudi-led coalition in Yemen said it had intercepted a Houthi drone early on Monday fired towards Khamis Mushait, however did not confirm any bases were hit.
Saudi Arabia intervened in Yemen's war in March 2015 to restore the authority of exiled President Abedrabbo Mansour Hadi.
The war in Yemen has spawned the world's worst humanitarian crisis, leaving millions suffering from food and medical shortages.
It has killed some 130,000 people, including fighters and civilians, according to a database project that tracks the violence.