Yesterday, an air strike on a school in the city's opposition-controlled east killed five children, three women teachers and a man.
The rebel education authority in Aleppo called on schools and teaching centres to suspend their classes until the end of the week, according to a statement distributed by the Syrian Observatory for Human Rights.
It said the decision was made "out of concern for the safety of students and teachers, because the criminal regime is targeting gatherings, schools, and institutions".
"The 135 schools as well as the markets are all closed," said the activist, who spoke on condition of anonymity.
Yesterday, bloodstains and debris marked the entrances of the bombed-out school, and broken desks and glass were strewn across classroom floors.
"People are more afraid than usual and there are dozens of families who have fled to refugee camps in Turkey or are internally displaced in Aleppo," the activist added.