Twenty-three female high school students fainted yesterday, leaving the principal, Touch Vuthy, at a loss to explain the phenomenon.

Vuthy, head of the Hun Sen Peam Chikorng High School in Kampong Cham province’s Peam Chikorng commune, said the students fainted after arriving for class at about 7:30am.

“I really do not know what the cause of the fainting is. But I am sure that they did not faint because of poisonous food or bad smells, since the school environment is good,” Vuthy said.

The students – all aged between 17 and 18 – were sent to the Prey Chhor district hospital and the provincial hospital.

A doctor at the provincial hospital, Kim Suorphirun, said they suffered from a lack of oxygen to the brain.