There have been a growing number of disruptions in the railroads, in Russian occupied Ukraine, that carry most of the supplies from Russia to Russian forces inside Ukraine. Ukrainian civilians in Russian occupied territory were inspired to sabotage rail lines because of the early example of anti-Russia Belarusians who sabotaged the few rail lines crossing the Ukrainian border.
Russia tried to shut down Ukrainian rail traffic early in the war with air and long-range missile attacks, but the internal railway system was so dense, and track repair capabilities so quickly expanded, that track damage was rapidly fixed and there were usually ways to reroute traffic until repairs were completed. Ukraine has 22,300 kilometers of railway and employs over 400,000 people to operate nearly 2,000 locomotives, 85,000 freight and 4,000 passenger cars. The Ukrainian railroad had its own telephone system, running next to the tracks. Early in the war, the railroad telephone was one uninterruptible form of communication. Recently Russia tried another approach to disrupting Ukrainian railroads by bombing electrical power generating facilities all over Ukraine.
Russia has a much larger railroad system with 161,100 kilometers of railway and employs over 800,000 people to operate nearly 19,700 locomotives, 796,000 freight and 24,200 passenger cars. The railroad system has many choke points (bridges and tunnels) inside Russia and some of these are shut down because of deferred maintenance or natural.
Until early March Russia had no problem using railroad crossings from Belarus, where six rail lines cross into Ukraine. In early March Belarussian railway employees were found to be cooperating with their Ukrainian counterparts to sabotage Russian rail traffic from Belarus to Ukraine. Belarus had refused to send troops into Ukraine but has been forced to allow Russian troops to operate in Belarus and cross into Ukraine via railroad. The pro-Russia Belarus government was forced to divert some of its few reliable military units to guard the rail crossings. This did not stop the sabotage but slowed it down. Most Belarussians oppose the Russian invasion of Ukraine as well as their own pro-Russia ruler, who was recently helped by Russian troops moved into Belarus to help suppress the growing number of demonstrations against the unpopular Belarussian ruler and Russia in general.