The calculated distance (air line) between Biskra and Oum el Bouaghi is approximately 105 miles respectively 170 kilometers.
By car or train, the actual journey to Oum el Bouaghi is certainly longer, as only the direct route (as the crow flies) between Biskra and Oum el Bouaghi has been calculated here.
Air line (approximately)
170 kilometers
92 nautical miles