The mastermind of the 17th of February terror attack on the Karachi Police Office and his accomplice were killed during an encounter, the Counter-Terrorism Department (CTD) said today.<br />''<br />''Iriadullah, the mastermind behind the attack, was gunned down after the CTD acted on a tip-off near the Northern Bypass in the Manghopir area of the metropolis. <br />''<br />''The two terrorists, including the mastermind, were killed during an exchange of fire, while two others were arrested, the CTD officials said. Iriadullah, according to the CTD, was a commander of the banned Tehreek-e-Taliban Pakistan (TTP) Karachi, while the second terrorist killed was identified as Abdul Waheed.<br />''<br />''<span style="color: #222222;">Last month, three terrorists with suicide jackets entered the multi-storey Karachi Police Office building. All three terrorists were killed in the operation and four persons, including two policemen and a Sindh Rangers sub-inspector, also died in the operation that lasted for more than four hours.</span><br />