LONDON: Prime Minister Nawaz Sharif on Sunday said initial investigation into the Bacha Khan University attack revealed that the attackers came from Afghanistan.

Speaking to media in London, the PM however clarified that he is not accusing the Afghan government of involvement in the attack, adding that some elements from the neighbouring country are responsible for terrorism inside Pakistan.

Related: APS mastermind claims Bacha Khan University attack, 21 killed

The premier said Pakistan and Afghanistan had agreed not to allow their respective soils to be used against the other.

"Pakistan is fully abiding by the agreement, so should the Afghan government." said Nawaz.

Answering a question about the Pathankot attack, the premier said that Pakistan is working on the leads provided by India and will also send a team to India to investigate the attack.

Related: Pakistan reiterates support to India on Pathankot incident

BKU attack

At least 21 people were killed when unidentified gunmen entered Bacha Khan University in Khyber Pakhtunkha’s Charsadda town Wednesday 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 has claimed the attack through a post on his Facebook page, adding that four attackers were sent to the university.

Inter Services Public Relations (ISPR), in a press conference on Saturday, too claimed that the attackers came from Afghanistan.

Related: 'Facilitators' behind BKU attack revealed after DG ISPR's press conference