GUWAHATI, March 12: The Bureau of Investigation of Economic Offences (BIEO) grilled four officials of Punjab tiol Bank (PNB), Zoo Road Branch, Guwahati on Monday in connection with scandal of the bank. The officials grilled are AGM Dhirendra Kumar Choudhury, Chief Mager Anil Tiwari, Mager Bharat Singh and accountant Pranjit Bhuyan.