Dozens of students and teachers at a girls school in Afghanistan's capital Kabul fell ill Wednesday by an unknown gas that spread through classrooms, education officials said.

Afghan schoolgirls receive treatment in a hospital after they were poisoned in Kabul on Wednesday. (Omar Sobhani/Reuters)

The incident was similar to earlier cases where scores of girls have been treated for dizziness, headaches and nausea following suspected poisoning attacks.

Those have raised fears that the Taliban and other Islamic fundamentalists who oppose female education are using a new method to scare them away from classes.

A total of 60 students and teachers from the Totia Girls School were treated, with all but a handful discharged by late afternoon, said Education Ministry spokesman Mohammad Asif Nang.

Nang said the incident is under investigation.