"Most of the patients we have received are not in critical condition," Ibrahim Monib, a doctor at the hospital, said.
There have been similar cases of illnesses at girls' schools around Afghanistan.
In separate incidents in Kunduz province in April and May, at least 80 school girls reported symptoms such as headaches, vomiting and shivering after suspected poisoning.
Some suspect groups which oppose education for girls are spraying schools with poison gas.
During Taliban rule, from 1996-2001, girls were banned from attending school.
In parts of southern and eastern Afghanistan, particularly in Taliban strongholds, schools for girls still remain closed.