On December 22, 1975, he was taken hostage along with Iran's Minister Jamshid Amouzegar, Zaki Yamani (Saudi Arabian Oil Minister) and twelve other Oil Ministers in a terror attack on OPEC headquarters in Vienna, Austria. Masterminded by Ilich Ramírez Sánches, known as "Carlos the Jackal," the OPEC siege left several dead. The hostage crisis came to an end, in Algiers, Algeria after several days, multiple flights to several countries, payment of $60 million, by Iran and Saudi Arabia, all mediated personally by then Algerian President Houari Boumédièan.