ISLAMABAD: The Foreign Office on Monday summoned the Afghan Charge d’Affaires, Syed Abdul Nasir Yousafi, to convey Pakistan’s concern regarding the use of Afghan soil by terrorist elements in the Bacha Khan University attack, said a statement issued from the FO.

It said the diplomat was summoned on Monday and was told that investigations revealed the perpetrators of the deadly attack on the varsity were operating from Afghan territory and used the Afghan telecommunication network.

The statement further said relevant evidence had also been shared with the Afghan diplomat. It was conveyed to the Afghan government that they must take action against the perpetrators of the terrorist attack and extend cooperation to Pakistani authorities in order to bring them to justice, it added.

At least 21 people were killed when unidentified gunmen entered the university in Charsadda town last week and opened fire on students and faculty members.

The mastermind of the APS Peshawar attack, Umar Mansoor, of the banned Tehreek-i-Taliban Pakistan (TTP) Geedar group claimed the attack through a post on his Facebook page, adding that four attackers were sent to the university.

Authorities say the Bacha Khan University attack was planned and orchestrated by Pakistani Taliban militants based in neighbouring Afghanistan, and has called on the Afghan government to co-operate in its investigation.

Five suspects have so far been arrested for acting as “facilitators” to the attack, Pakistan Army’s media wing said Saturday .