The CID became the target of the attack as it is spearheading the drive against terrorists in Karachi. The Tehrik-e-Taliban, the Pakistan-arm of the banned militant group, not only claimed responsibility for the strike but also warned of more terror attacks saying that the next target would be the Presidential Palace in Islamabad.
After detonating an explosives-laden truck at the office at around 8:17 pm (local time), the attackers exchanged fire with guards outside the CID office.
The office is located in high security area with the Chief Minister's official residence and several five-star hotels and consulates in the vicinity.
Most of those killed in the attack were policemen and security personnel. The area around the CID office was cordoned off after the attack and an emergency was declared in hospitals.
The local media gave varying accounts on the number of attackers. It is also unclear if the militants were also among the dead.