According to eye witness reports there was an exchange of gunfire prior to the blasts that continued for 30 minutes. Sindh Home Minister Zulfiqar Mirza also confirmed that five to six people opened fire before the explosion.According to Ahmed Jung, sources claimed that the CID had received a bomb threat yesterday (Wednesday). CID had arrested a high profile terrorist 'Iqbal' belonging to the Mehsud tribe yesterday and had received a threat in that regard.A lot of data on terrorists is feared to be lost in this explosion.So far,people are being reported dead, while more thanhave been injured. According to Express 24/7 Correspondent Ahmed Jung, the number of injured is expected to rise. Two FC officials were found injured inside the building. Women and children have also been wounded in the attack.Hospitals aredonations for the injured.Express 24/7 Masror Hausen reports that 80 to 90 people have been brought into Jinnah Hospital, who were not critically injured.According to Masror Hausen, in the initial panic outside Jinnah Hospital, Rangers arrested a person carrying a gun. The man claimed that he was a member of the CID. However, he did not have an ID card and so he was arrested.The blast is said to have occurred from aor truck which drove into the building following an exchange of gunfire in the area. Home Minister Zulfiqar Mirza confirmed this report. According to Ahmed Jung, 200kg of explosives were used in the blast. The police has also reportedly found hand grenades at the site of the blast.According to Express Tribune reporter Hafeez Tunio, the CID building has been flattened in the blast, while roof of nearby houses have collapsed. Windows of buildings as far as the Marriot were also shattered by the intensity. The whole colony around the blast site was also severely damaged.Ahmed Jung reports that the blast caused a 12 to 15 feet wide crater in the ground at the entrance of the building, while 16 to 20 nearby houses were heavily damaged.Express News Correspondent Nadeem Khan reports the intensity of the explosion was such that it was heard for many kilometers around and nearby buildings have been damaged. According to officials the blast intensity was the highest to have been witnessed in Karachi in recent years.The explosion took place in a central, highly sensitive area of Karachi. Aside from the PIDC building, there is also the Chief Minister House, Governor House, Pearl Continental Hotel and Sheraton hotel in the area.Former CPLC Chiefsaid that the aim of the explosion could have been to rescue terror suspects who were were being kept in the building. He added that the injured who are being taken to the hospitals could have those suspects within them and security at the hospitals should be aware of this as their accomplices could try to rescue them from there as well.Renowned social worker, who was present at Jinnah Hospital said this attack was not the work of a human being or a Muslim. He said that terrorists are roaming around Karachi, and we do not know what their aim is.CPLC Chiefsaid that if a terrorist comes on a mission, he is fully prepared to give his life adding that there is need for pre-emptive measures and information gathering on people who enter the city. He said that this building was a softest target for the terrorists in the area.Sindh Information Ministersaid that the government is not fully equipped to combat such incidents. The government is working on intelligence sharing. She said that the government needs funds to fully equip the police.She said that she calls upon everyone to give strength to the government, the police and the army to combat terrorism adding that we are in a state of war and everybody is vulnerable.