The explosion took place around 9.40 a.m. inside a classroom of the Literature Faculty in the University of Ghazni while a session was underway, the provincial governor's spokesperson, Arif Noori, told Efe news.
Ghazni police spokesman Ahmad Khan Sirat said that as per the latest information, 23 university students had been injured in the blast, which was caused by an Improvised Explosive Device.
"Unfortunately, most of those injured in this terrorist incident are girls," he said.
Noori had reported that the injured included 12 women and two of them were in a critical condition.
"Some of the students who are coming from remote and insecure areas of Ghazni province have contacts with the militants and we think they might be behind this blast," the governor's spokesperson said.
He added that many students had been detained earlier for allegedly having links with the militants.
The Taliban has denied carrying out the blast and condemned it on social media, while no other insurgent group has claimed responsibility so far.
"We got the news of a blast inside Ghazni University. The Islamic Emirate strongly condemns this act; targeting educational institutions is against Islamic and humanitarian principles," Taliban spokesperson Zabiullah Mujahid tweeted.
The attack comes a day after a bombing targeting a bus carrying army recruits in Nangarhar province killed 10 people and injured 27, most of them civil.
( With inputs from IANS )