Gunmen have stormed Kabul University ahead of the opening of an Iranian book fair, wounding at least six people, government officials say.
Interior ministry spokesman Tariq Arian said several gunmen had entered the campus, sending students fleeing.
He said security forces had blocked the campus and fired back at the gunmen.
The Taliban denied involvement in the attack. Afghan education centres have often been targeted by militants in recent years.
“We don’t know whether we are dealing with a coordinated attack or something else,” Mr Arian said.
Hamid Obaidi, a spokesman for the ministry of higher education, told the AFP news agency that the attack began when government officials were expected to arrive for the opening of the fair.
Video footage from the scene showed students walking and running away from the university, with the sound of gunfire in the background. Some scaled walls in an effort to escape.
Masooma Jafari, deputy spokeswoman for the health ministry, told AFP four people had been taken to hospital.
Last month, an attack outside a tuition centre in Kabul by the Islamic State group left 24 people dead. The group also claimed responsibility for a 2018 attack in front of the university in which dozens were killed.
Violence in Afghanistan has worsened in recent months even as the Taliban conducts peace talks with the government in Doha, Qatar. A senior UN official told the BBC last week that al-Qaeda was still “heavily embedded” within the Taliban, despite assurances from Taliban officials to the US that it would sever ties with the terror group.