The National Accountability Bureau (NAB) on Friday opened various cases on Supreme Court orders, sources said. Notices were issued to Ismail Qureshi, Raja Ahsan and Adnan Khwaja. Khwaja among various others already presented themselves before the NAB, the sources added. According to sources, Malik Qayyum could not be arrested being abroad whereas; Punjab police is not cooperating for the arrest of Ahmad Riaz Sheikh.