evidence: European security officials on Monday and Tuesday observed Russian Navy support ships in the vicinity of leaks in the Nord Stream pipelines likely caused by underwater explosions, according two Western intelligence officials and one other source familiar with the matter. [...] If Russia did deliberately cause the explosions, it would be effectively sabotaging its own pipelines: Russian state company Gazprom is the majority shareholder in Nord Stream 1 and the sole owner of Nord Stream 2. [...] The US warned several European allies over the summer, including Germany, that the Nord Stream 1 and 2 pipelines could face threats and even be attacked, according to two people familiar with the intelligence and the warnings.