The calculated distance (air line) between Mostaganem and Aïn Oussera is approximately 162 miles respectively 260 kilometers.
By car or train, the actual journey to Aïn Oussera is certainly longer, as only the direct route (as the crow flies) between Mostaganem and Aïn Oussera has been calculated here.
Air line (approximately)
260 kilometers
140 nautical miles