Doctors in northern Afghanistan say they are treating more than 120 Afghan girls for possible poisoning after they became sick at school.
The head of Takhar Province's education department Abdul Wahab Zafari said the students noticed what he called "a certain smell" in the school before becoming sick on Wednesday.
One of the girls said she saw a student unconscious and in bad condition. The girl said she and many others passed out after drinking the water.
While no one claimed responsibility for the incident, the Taliban frequently target female schools with poison and acid attacks in an effort to close them down. Under the Taliban's rule, women were banned from working or going to school outside the home.
Elsewhere in northern Afghanistan, officials said unidentified gunmen kidnapped two foreign doctors and three of their Afghan colleagues Tuesday.
A spokesman for the governor of Badakhshan province said the kidnapping happened as the group was traveling on horseback in the Yaftal area. Officials said the aid workers were with a non-profit humanitarian organization, but did not identify them.
Badakhshan is a mountainous part of Afghanistan bordering Pakistan. While it has not been a focus of insurgent activity during the Afghan war, militants have carried out sporadic attacks in the province.
Last month, a group of Taliban insurgents ambushed a police post, killing at least four police officers and capturing 16 others. In 2010, the Taliban claimed responsibility for the killing of 10 Christian medical workers, whom it accused of acting as spies and missionaries.
Meanwhile, Afghan intelligence agents said they arrested five suspected insurgents for allegedly attempting to carry out a suicide attack near Kabul international airport.
Authorities say the would-be attackers had 560 kilograms of explosives in their minivan at the time of their arrest. It was not immediately clear if the airport was the target.
In other violence Wednesday, NATO officials said a coalition service member died following an improvised explosive device attack in the southern part of the country. Officials did not release the service member's nationality.
Some information for this report was provided by AP, AFP and Reuters.