The United Arab Emirates central bank has told banks to freeze the assets of two former senior officials in Abu Dhabi's state-owned International Petroleum Investment Co (IPIC) group, banking sources told Reuters.  In a circular, the central bank directed some major banks operating in the UAE to freeze the accounts of Khadem al-Qubaisi and Mohamed al-Husseiny and provide information about their deposits and transactions, the sources said. The circular did not say why the central bank was taking this action, and the central bank did not respond to a Reuters email seeking comment on Thursday. The sources spoke on condition of anonymity because of commercial sensitivities. Qubaisi was one of the most prominent executives in the UAE until he was abruptly replaced as IPIC's managing director in April last year. In subsequent months he stepped down as chairman of IPIC's unit Aabar Investments and from senior posts at several other firms in the region.  Husseiny was replaced as chief executive of Aabar last year after holding that post since 2010. (Reuters)