The calculated distance (air line) between Al Muharraq and Al Ḩadd is approximately 3 miles respectively 4 kilometers.
By car or train, the actual journey to Al Ḩadd is certainly longer, as only the direct route (as the crow flies) between Al Muharraq and Al Ḩadd has been calculated here.
Air line (approximately)
4 kilometers
2 nautical miles