A former CIA officer Bruce Riedel has said that US should tell Pakistan in clear terms that it will go after Major Iqbal, the ISI official who is believed to be the mastermind of the Mumbai terror attacks. Riedel, who is now with the prestigious Brookings Institute said at the Center for Strategic and International Studies, a Washington-based think tank said that if the ISI officer who worked with David Headley to set up the attack on Mumbai is identified, his assets will be grabbed, he will be arrested or US can go after him with extreme measures. Iqbal has been charged by the FBI for his involvement in the Mumbai terror attacks that killed 166 people including six Americans. US Attorney Patrick Fitzgerald last week vowed to bring Major Iqbal to justice. Fitzgerald told reporters after a Chicago jury gave its verdict on Tahawwur Rana case which found him guilty on two counts of terror charges. Following the verdict, the US attorney vowed to bring the other six Pak-based defendants to justice who has been named in the indictment filed by federal prosecutors. Besides Iqbal, the other five are Illyas Kashmiri, the Al Qaeda leader; Sajid Mir, the Lashkar-e-Taiba commander; and Abdur Rehman Hashim Syed aka Pasha; another LeT leader; all of whom are charged to be involved in the Mumbai terrorist attack, besides plotting a major terrorist attack in Denmark.