The official said that the wounded persons were university students and that they were all taken to hospitals.
Later, a civilian source in a medical facility said that a total of 15 injured students, 13 females and two males, were rushed to Ghazni Civil Hospital.
The blast occurred at around 10:00 a.m. local time (5:30 GMT) inside the department of the Dari Literature Faculty.
The bomb was placed in a classroom, a university source said.