The National Investigation Agency (NIA) has announced a reward of 5 lakh rupees for any information related to the Delhi high court blast. Union Home Secretary RK Singh on Thursday said in New Delhi that shrapnel was used in the blast to maximise the impact and casualties.On Wednesday, officials had claimed that shrapnel was not used in the blast as it was carried out using pentaerythritol tetranitrate (PETN), which is a plastic explosive. Mr.Singh has also received the preliminary forensic report on the blast.The home secretary added that investigators have also traced the origin of the e-mail claiming responsibility for the blast to the Global Cyber Cafe situated in Kishtwar district of Jammu and Kashmir. The owner of the cyber cafe and three others have been detained and are being questioned.The e-mail was reportedly sent by terror group Harkat-ul-Jehadi Islami (HuJI) but sources say that it could also be a red herring as the organisation is not know to claim responsibility about the terror strike through e-mails.The home secretary also ruled out the possibility of the involvement of a Hyundai i-10 car which was recovered from Faridabad near New Delhi on Thursday in the case.Meanwhile, the death toll in the blast has risen to 12 after a victim succumbed to his injuries early this morning. Ninety-one people have been injured and some of them face amputation due to injuries caused by shrapnel.Union Home Minister P Chidambaram chaired a meeting of the chiefs of the Research and Analysis Wing, Intelligence Bureau and NIA Thursday morning to review the security situation.