Pakistani police say gunmen have stormed a university in the country's northwest and have wounded at least five people in the attack.

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 35 kilometers (21 miles) outside the city of Peshawar.

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.