Kabul, Afghanistan (CNN) -- A hospital in northern Afghanistan admitted 160 schoolgirls Tuesday after they were poisoned, a Takhar province police official said.
Their classrooms might have been sprayed with a toxic material before the girls entered, police spokesman Khalilullah Aseer said. He blamed the Taliban.
The incident, the second in a week's time, was reported at the Aahan Dara Girls School in Taluqan, the provincial capital.
The girls, ages 10 to 20, complained of headaches, dizziness and vomiting before being taken to the hospital, said Hafizullah Safi, director of the provincial health department.
More than half of them were discharged within a few hours of receiving treatment, Safi said. The health department collected blood samples and sent them to Kabul for testing.
Last week, more than 120 girls and three teachers were admitted to a hospital after a similar suspected poisoning.
"The Afghan people know that the terrorists and the Taliban are doing these things to threaten girls and stop them going to school," Aseer said last week. "That's something we and the people believe. Now we are implementing democracy in Afghanistan and we want girls to be educated, but the government's enemies don't want this."
But earlier this week, the Taliban denied responsibility, instead blaming U.S. and NATO forces for the poisonings in an attempt to "defame" the insurgent group.
There have been several instances of girls being poisoned in schools in recent years.
In April, also in Takhar province, more than 170 women and girls were hospitalized after drinking apparently poisoned well water at a school. Local health officials blamed the acts on extremists opposed to women's education.
While nearly all the incidents involve girls, earlier this month, nearly 400 boys at a school in Khost province fell ill after drinking water from a well that a health official said may have been poisoned.
The Taliban recently demanded the closure of schools in two eastern provinces. In Ghazni, the school closure was in retaliation for the government's ban on motorbikes often used by insurgents. People in Wardak said the Taliban has been a little more lenient and has allowed schools to open late after making changes to the curriculum.
The battle indicates broader fears about Afghanistan's future amid the drawdown of U.S. troops in the country.
NATO leaders last week signed off on U.S. President Barack Obama's exit strategy from Afghanistan, which calls for an end to combat operations next year and the withdrawal of the U.S.-led international military force by the end of 2014.
During the Taliban's rule from 1996 to 2001, many Afghan girls were not allowed to attend school. The schools began reopening after the regime was toppled by the U.S.-led invasion in 2001. However, observers say abuse of women remains common in the post-Taliban era and is often accepted in conservative and traditional families, where women are barred from school and sometimes subjected to domestic violence.
Afghan Education Minister Dr. Farooq Wardak told the Education World Forum in London in January 2011 that the Taliban had abandoned its opposition to education for girls, but the group has never confirmed that.