A northwestern Pakistani university has resumed classes amid heightened security nearly a month after Taliban militants stormed the campus, killing 21 students and teachers.

The Jan. 20 attack revived memories of the horrific December 2014 Taliban attack on an army run school in the nearby city of Peshawar that killed 150 people, most of them schoolchildren. The same Pakistan Taliban faction claimed responsibility for both attacks.

The Bacha Khan University's Vice Chancellor Fazl-ur-Rahim Marwat on Monday welcomed the students back, assuring them all possible security measures have been taken.

The university in the town of Charsadda is named after liberal, secular political figure hailed as a spiritual leader by an anti-Taliban political party. All four attackers were killed in the shootout with Pakistani troops at the Charsadda campus.