"At 8:30am (0400 GMT) this morning, tragically, nine schoolchildren were martyred in a landmine blast planted by the Taliban," Jawad Hejri, a spokesman for the Takhar provincial governor, told AFP.
He said the children - all boys - were aged from seven to 11.
No group claimed responsibility for the blast, and the Taliban did not immediately respond to a request for comment. Last month, the United Nations released a report saying an "unprecedented" number of civilians were killed or wounded in Afghanistan from July to September this year.
The figures - 1,174 deaths and 3,139 injured from July 1 until September 30 - represent a 42 percent increase compared to the same period last year.