At least 20 people were killed by gunmen on Wednesday at Bacha Khan University in Charsadda, about 140km from the capital Islamabad.
The gunmen accessed the university by scaling a wall and cutting through barbed wire. They eventually managed to kill students and a professor.
Reports say the attack took at least 6 hours but all the attackers were killed by Pakistan security forces.
According to Pakistan army, the death toll could rise significantly as more bodies are being retrieved. More than 50 people were injured in the attack.
“The operation is over and the university has been cleared,” Pakistan army spokesperson General Asim Bajwa told Reuters news agency.
“Four gunmen have been killed”, they added