ISLAMABAD, March 22 (INP): Railways Minister Khawaja Saad Rafique requested on Thursday the National Accountability Bureau (NAB) Lahore to postpone questioning him in a housing scam. NAB Lahore had summoned the federal minister and his brother, provincial minister Khawaja Salman Rafique, in relation to a corruption probe into a private housing scheme reportedly owned by them in Lahore. INP/AJ