The calculated distance (air line) between Ashmūn and Diyarb Najm is approximately 42 miles respectively 68 kilometers.
By car or train, the actual journey to Diyarb Najm is certainly longer, as only the direct route (as the crow flies) between Ashmūn and Diyarb Najm has been calculated here.
Air line (approximately)
68 kilometers
36 nautical miles