Aircraft attacked by fighter. Rear turret guns U/S and intercomm U/S. Cannon shells entering fuselage set oil alight. Mid upper turret and intercomm U/S. Bomb doors fell open owing to hydraulic system being U/S. IFF aerial found severed. TR U/S. 4 x 1900lb bombs jettisoned. 1 x 1900lb hung up and brought back. Landed at Wittering.