Kabul: About 20 Afghan girls were hospitalised after falling ill in their school, and authorities said Wednesday they suspect their classroom's recent fumigation was to blame but were investigating whether it was a poison attack.

Several group poisonings in girls' schools in the country's northeast this year have raised fears that the Taliban and other Islamic fundamentalists who oppose female education are using a new method to scare them into staying away from classes.

Qameruddin Shakib, the deputy governor of northern Sar E Pul province, said students in one class in the Gawharshad Begom high school fell ill Tuesday in a room that had recently been sprayed with insecticide.

"We doubt any militant involvement, but we need to investigate it deeply and make ourselves sure about it," Shakib told The Associated Press.

The girls became sick after spending about 20 minutes in the classroom, with some vomiting and others feeling unstable and unable to stand up, he said.

About 20 students were taken to a hospital for treatment, and all were released after several hours.

Girls schools have regularly come under attack or have been burned down by militants, and some students have had acid thrown on them in what officials say are intimidation tactics.

More than 100 people were hospitalized after the earlier poisoning cases in Kabul and two regions just north of the capital. No one has claimed responsibility for any of the attacks.