U.K.-based charity Save the Children said Thursday that more than three-quarters of school-age children in war-torn Sudan are out of school, creating one of the world’s worst education crises.

A new study by the charity revealed that 13 million out of 17 million school-age children in Sudan are not attending classes.

All 13 million children have been out of school since at least April 2023, meaning they have now lost more than two academic years to violence, the study said.

This figure includes around 7 million children who are enrolled but unable to access education due to ongoing conflict or displacement and another 6 million who are not enrolled at all and risk losing their right to an education entirely, the study showed.

Since April 2023, Sudan has been torn apart by a brutal war between the army and the paramilitary Rapid Support Forces (RSF).