Two million children are out of school in Yemen, a quarter of whom have dropped out since the conflict escalated in March 2015, bearing the brunt of the ongoing war, the U.N. children' agency has said.

The education of a further 3.7 million children is at risk as teachers' salaries have not been paid in over two years, UNICEF said in a statement. "Violence, displacement and attacks on schools are preventing many children from accessing school," said Sara Beysolow Nyanti, the UNICEF representative in Yemen. One in five schools in the country can no longer be used as a direct result of the conflict that has devastated Yemen's already fragile education system, according to the U.N. agency. "Children out of school face increased risks of all forms of exploitation including being forced to join the fighting, child labor and early marriage," Nyanti said.

Saudi Crown Prince Mohammed bin Salman, who is the former Saudi defense minister, and Saudi Arabia's allies launched Operation Decisive Storm in March 2015. The ongoing war has resulted in the worst humanitarian crisis in the world, with an estimated 24 million people, close to 80% of the population, in need of assistance and protection in Yemen, according to the U.N. The Saudi-led coalition is continuing to target residential areas, with the latest U.N. report showing that 729 Yemeni children were killed or injured during 2018. Save the Children reported in March that 37 Yemeni children a month had been killed or injured by foreign bombs in the last year. Many atrocities have been reported so far, which have revealed multiple violations of human rights.