Major leaks blamed on sabotage on the subsea Nord Stream gas pipelines from Russia to Europe have put governments from Oslo to Rome on high alert and prompted some to send in the military to secure what they see as increasingly vulnerable energy systems.
Norway, Western Europe's biggest oil and gas producer, has sent troops to guard its energy installations, Italy has stepped up naval surveillance on pipeline routes and German grid operators are increasing the security of its transmission lines.
Europe's energy crisis, sparked by Russia's invasion of Ukraine, has escalated from a problem of ensuring supply to a challenge of securing the networks that keep Europe warm and the lights on as the colder, darker months of winter approach.