Police in Pakistan have detained 23 people in connection to a blast at a mosque inside a police headquarters that killed 101 people, a senior official who asked not to be named.
Authorities are also probing the possibility that people inside the compound helped to coordinate the attack, the senior provincial police official told AFP on condition of anonymity.
"We have detained people from the police line (headquarters) to get to the bottom of how the explosive material made its way in and to see if any police officials were also involved in the attack," the senior official said on Wednesday.
A suicide bomber slipped undetected into a highly sensitive compound in northwest Peshawar and detonated explosives among a row of worshippers in the compound's mosque on Monday, causing a wall to collapse and crush officers.
He said some among the 23 detained were also from the city and nearby former tribal areas which border Afghanistan.
Authorities are investigating how a major security breach could happen in one of the most tightly controlled areas of the city, housing intelligence and counter-terrorism bureaus, and next door to the regional secretariat.
