A third of schools have been closed and only one in four teachers are still working in the hardest-hit areas of Hudaydah.
More than 60,000 children have had their education disrupted by fierce fighting in the port city of Hudaydah in Yemen.
Over a third of schools have been forced to shut because they are either on the frontline of the conflict or are being used as shelters for displaced families.
"Schools running double shifts in the area have had to scale back to just a few hours of instruction in the morning," said Meritxell Relaño, UNICEF Representative in Yemen.
Fewer than one in four teachers are still able to teach in the worst-affected areas of Hudaydah. Most teachers and education staff in Yemen have not been paid for more than two years.
“Despite the many hardships they face, countless teachers across Yemen continue to educate children in any way that they can," said Relaño. "Their commitment to keep children learning is nothing short of heroic."
In October the United Nations children's agency said that it would soon start making monthly payments to unpaid teachers.
Hudaydahh is controlled by the Houthi rebels, who have been bombarded by coalition warplanes in recent weeks. The port is the centre for a majority of the country's imported food and medicines.
The conflict in Yemen has put more than two million children out of school. One in five schools cannot be used because they are destroyed, damaged, sheltering displaced families or being used for military purposes.
Relaño added: “There is no aspect of a child’s life in Yemen that isn’t deeply impacted by the conflict. As the war on children in Yemen continues to injure and kill, the violence is also having a profound effect on children’s education – and their prospects for a brighter future.
"Parties to the conflict should immediately stop the fighting and refrain from military activities in and around schools in Hudaydah and across Yemen, to keep students, teachers and other education staff out of harm’s way and give education a chance."