The calculated distance (air line) between Mostaganem and Ksar el Boukhari is approximately 149 miles respectively 240 kilometers.
By car or train, the actual journey to Ksar el Boukhari is certainly longer, as only the direct route (as the crow flies) between Mostaganem and Ksar el Boukhari has been calculated here.
Air line (approximately)
240 kilometers
129 nautical miles