PH
The police and army are exchanging gunfire with the attackers and several explosions have been heard from the area of the university.
Police official Tariq Khan says the assault that began shortly after the university opened on Wednesday morning in the town of Charsadda, located some 35km outside the city of Peshawar.
Police say a gunmen has killed a professor and a student in the attack already.
No one has claimed responsibility for the attack.
The Bacha Khan University is named after the founder of a liberal, anti-Taliban political party. Pakistani Taliban have in the past targeted the party for its anti-militant policies.
A Taliban attack on a school in Peshawar in December 2014 killed over 150 people, mostly children.
