The blast targeted a facility of intelligence agency National Directorate of Security in the provincial capital city, also Ghazni, said Arif Noori, a spokesman for provincial governor.
Wahidullah Mayar, a spokesman for Public Health Ministry, said that the attack left 12 people dead and 179 more wounded.
Earlier, Arif Noori, a spokesman for provincial governor, said six people who were killed in the bombing included two security personnel and four civilians. 97 injuries included nine security personnel and 88 civilians, he said.
The injuries included women and many children who were students.
Taliban claimed responsibility for the attack.
The violence comes hours before a two-day dialogue conference involving Taliban and other Afghans began in Qatar capital Doha.
Source : Afghan Voice Agency(AVA)