One more person injured in Wednesday's blast outside the Delhi High Court premises, died at a hospital in Delhi today taking the toll in the incident to 12. The condition of four of the victims continues to be critical. Home Minister P Chidambaram on Friday held a high-level meeting to take stock of situation in wake of the Delhi blast. National Security Advisor Shivshankar Menon was also present in the meeting. Union Home Secretary R K Singh said that the initial forensic reports in connection with Delhi High Court blast have been received. Secretary Internal Security in the Home Ministry U.K. Bansal told reporters that about two kilogram of explosives were used in the blast and the explosives could be nitrate based. A high intensity briefcase bomb had ripped through the crowded reception area in the Delhi High Court on Wednesday. 75 people were injured in the blast that took place between Gate No.4 and 5 when around 200 visitors, mostly litigants, were waiting in queue to get passes to enter the premises. Out of the 57 injured admitted to RML hospital, two were later transferred to AIIMS. Four blast victims have been admitted to AIIMS. Hospital sources said, that around 12 patients are recuperating in RML's surgical ward, 19 are still in the ICU and two are at the new nursing home. Sunil Saxena, CMO of RML said, the hospital will provide all care and facility that is needed for the victims. Delhi Police has released sketches of two people suspected of planting the bomb in a suitcase outside the court, just two km away from Parliament House. The sketches of a 26-year-old and a 50-year-old man were prepared following the description provided by some eye- witnesses who claimed that they have seen a person in white shirt with a briefcase standing in the queue for entry passes. A 20 member National Investigating Agency team headed by a DIG is probing the incident. A massive manhunt and combing operation has been launched to bring the perpetrators of the blast to the book. NIA Chief S.C. Sinha said that it is too early to say which group is behind the terror attack but he made it clear that the agency will probe the involvement HUJI terror outfit who has claimed responsibility for the blast. AIR correspondent reports that movement of traffic along the road to the Delhi High Court has been restricted.