The Khyber Pakhtunkhwa (KP) Counter Terrorism Department (CTD) on Monday said it had arrested “four key terrorists” belonging to the banned militant Tehreek-i-Taliban Pakistan (TTP) group involved in the suicide attack in Bisham last month.

On March 26, five Chinese engineers — and their Pakistani driver — were killed in a suicide bombing in KP’s Bisham while travelling between Islamabad and a hydroelectric dam construction site in Dasu. The bus was attacked in the Bisham city of Khyber Pakhtunkhwa’s Shangla district.

The attack prompted China to demand a thorough probe into the deadly blast and security for its citizens. In response, Islamabad had announced a swift probe to hold the “perpetrators and accomplices” accountable. Chinese investigators had also arrived to join the probe.

In response to the Chinese government’s demand to promptly investigate the incident and act against those involved, the government had also decided to form a joint investigation team to probe the attack.

Earlier this month, Prime Mini­ster Shehbaz Sharif had ordered action against five senior police officers over negligence and security lapses, which led to the Bisham attack.

Terming the arrests a big headway, the KP CTD spokesperson said in a statement today that the department had arrested four suspects — Adil Shehbaz, Muhammad Shafiq Qureshi, Zahid Qureshi and Nazeer Hussain — who were residents of Mansehra district.

The statement said that all four arrested were linked with the TTP, adding that Shehbaz had “confessed to the attack”.

The CTD identified him as the mastermind, adding that Shehbaz had admitted to playing a pivotal role in the execution of the Bisham attack and that he was a resident of Afghanistan’s Jalalabad district.

He had also confessed to having links with TTP.