A splinter Taliban commander has claimed responsibility for the deadly gun-and-bomb attack on a university campus in northwestern Pakistan. 

Mullah Umar Mansoor, a dissident commander of the Pakistani Taliban’s mother group Tehrik-e-Taliban Pakistan (TTP), claimed responsibility for the attack on Bacha Khan University. 

The attack, which left 22 people dead, happened on Wednesday in Charsadda district, located some 40 kilometers from Peshawar. 

Mansoor is also considered the mastermind of the Peshawar school massacre in which more than 140 people, mostly students, were killed in December 2014. 

Pakistani intelligence agencies believe Mansoor is currently operating from Naziyan district in Afghanistan’s eastern Nangrahar province. 

Meanwhile, security forces have arrested four suspects for allegedly providing logistical support to the four attackers who carried out Wednesday’s attack.

Anadolu Agency