More than 120 schoolgirls and three teachers have been poisoned in the second attack in as many months blamed on conservative radicals in the country's north, Afghan police and education officials said on Wednesday.
The attack occurred in Takhar province where police said that radicals opposed to education of women and girls had used an unidentified toxic powder to contaminate the air in classrooms. Scores of students were left unconscious.
Afghanistan's intelligence agency, the National Directorate of Security (NDS), says the Taliban appear intent on closing schools ahead of a 2014 withdrawal by foreign combat troops.
"A part of their Al Farooq spring offensive operation is ... to close schools. By poisoning girls they want to create fear. They try to make families not send their children to school," NDS spokesman Lutfullah Mashal said.
Afghanistan's Ministry of Education said last week that 550 schools in 11 provinces where the Taliban have strong support had been closed down by insurgents.
Last month, 150 schoolgirls were poisoned in Takhar province after they drank contaminated water.
Since 2001 when the Taliban were toppled from power by US-backed Afghan forces, females have returned to schools, especially in the capital Kabul. They were previously banned from work and education.
But there are still periodic attacks against students, teachers and school buildings, usually in the more conservative south and east of the country, from where the Taliban insurgency draws most of its support.