On the night of 29-30 November, an explosion occurred on the Baikal-Amur Mainline in the Severomuysky Tunnel, named after Vladimir Bessolov, located in Buryatia (Russia).
Source: Ukrainska Pravda’s source in the security forces
Details: The source notes that this is actually the only major railway connection between Russia and China. And currently this route, which Russia uses, specifically for military supplies, is paralysed.
If Russia stealing everyone’s airplanes didn’t give anyone cassus belli, breaking one of Russia’s rail lines in Russia that China liked to use probably won’t.