<p><br /> Militants have attacked a police compound in the heart of Pakistan's largest city with a hail of gunfire and a massive car bomb, levelling the building and killing at least 15 people.<br /> </p><p><br /> The gang of around six gunmen managed to penetrate a high-security area of Karachi that is home to the US Consulate, two luxury hotels and the offices of regional leaders.<br /> </p><p><br /> While no stranger to extremist violence, Karachi has not witnessed this kind of organised assault in recent years.<br /> </p><p><br /> It was the first major attack against a government target outside the northwestern tribal regions for several months, showing the reach of Islamist militants seeking to overthrow the US-allied government despite efforts to crack down on them over the last three years.<br /> </p><p><br /> The gunmen first opened fire on the offices of the Crime Investigation Department (CID) before detonating a huge car bomb, said Sindh Home Minister Zulfiqar Mirza.<br /> </p><p><br /> The building has a detention facility that was believed to be holding criminals and possibly militants. The CID takes the lead in tracking down militants in Karachi.<br /> </p><p><br /> Earlier this week, the agency arrested six members of Lashkar-e-Jhangvi, an al-Qaida linked group blamed for several high profile attacks in recent years. The suspects appeared before a court earlier on Thursday.<br /> </p><p><br /> The blast could be heard several miles away in the city of 14 million people. It destroyed much of the multi-storey police building, damaged nearby houses and left a three-metre wide crater in the road.<br /> </p>
