Either way, the reports from three schools within two miles of one another in the northern province of Kunduz have raised alarm in a city threatened by the Taliban and their militant allies.
The latest cases were Sunday, when 13 girls became sick, Kunduz provincial spokesman Mahbobullah Sayedi said. Another 47 complained of dizziness and nausea the day before, and 23 fell ill last Wednesday.
All complained of a strange smell in class before they fell ill.
"I came out from the main hall, and I saw lots of other girls scattered everywhere," Anesa, a 9-year-old who was hospitalized briefly Sunday, told The Associated Press. "Then suddenly, I felt that I was losing my balance and falling."
None of the illnesses was serious and the girls were only hospitalized for a short time. The Health Ministry said blood samples were inconclusive and were being sent to Kabul for further testing to determine the cause of the illnesses.
"This is a matter of concern not only for us but for the families," Sayedi said, blaming the sicknesses on "enemies" who oppose education for girls.
In the capital of Kabul, President Hamid Karzai's spokesman, Waheed Omar, said any attempt to keep girls out of school is a "terrorist act."
Kunduz had been relatively quiet until a few years ago when Taliban activity began to increase, threatening NATO supply routes south from Central Asia. Late Saturday, NATO and Afghan troops killed one militant and detained several others in Kunduz province.
Girls were not allowed to attend school when the Taliban controlled most of Afghanistan. The group was ousted from power in the 2001 U.S.-led invasion. The Taliban and other conservative extremist groups have been known to target schoolgirls.
In one of the most chilling attacks, men on motorbikes sprayed acid from squirt guns and water bottles onto 15 schoolgirls and teachers in 2008 as they walked to a girls school in Kandahar, the southern city that is the spiritual birthplace of the militant movement.
Previous cases of sudden illness in schools have left families too frightened to send their daughters to school.
Last year, dozens of girls were hospitalized in Kapisa province, just northeast of Kabul, after many collapsed with headaches and nausea following reports of a strange odor in their schoolyard. The Taliban was blamed, but research into similar mass sickenings elsewhere has suggested that some might be the result of group hysteria.
Elsewhere in Afghanistan on Sunday, hundreds of people blocked a main road in Logar province, west of Kabul, and burned several trucks to protest what they said were civilian deaths in NATO operations. They gathered hours after NATO said coalition troops killed several insurgents and captured a Taliban sub-commander.
"The man they killed was a schoolteacher and a mullah," said businessman Jan Mohammed. "They killed him inside his house and because of that the people came and burned my gas station, my car and my house."
He complained that if NATO thought the mullah was with the Taliban, "they should have arrested him at his school, not gone to his house at midnight."
"The people are very angry. They are saying these people killed are innocent civilians," provincial spokesman Din Mohammad Darwesh said.
Civilian deaths caused by U.S. and other international forces are highly sensitive in Afghanistan. Public outrage over such deaths prompted the top commander, Gen. Stanley McChrystal, last year to tighten the rules on the use of airstrikes and other weaponry if civilians are at risk.
Last week, hundreds of residents in Logar protested another NATO operation, saying they were not convinced the victims were actually Taliban fighters. Logar is a strategic province because it controls southern land routes into Kabul, allowing weapons, explosives and fighters to move into the capital.
Also Sunday, NATO said a helicopter belonging to a civilian contractor made an emergency landing in Farah due to mechanical problems. There were no reports of injuries, NATO said. The Taliban claimed they shot down the helicopter.
In southeastern Afghanistan, a suicide bomber attacked private security guards while they were at a bazaar, killing four Afghans and wounding 12, the government said.
Two of the dead and five of the wounded worked for the U.S. Protection and Investigations security firm, an Interior Ministry statement said. The other victims were civilians.
The Houston-based company could not immediately be reached for comment.
The suicide attacker, who was on foot, targeted the guards at a bazaar in Sahjoy district of Zabul province, the ministry said.
By Associated Press Writer Rahim Faiez