Norwegian police on Friday investigated reports of a drone that was spotted flying over the Kaarstoe gas processing plant in southwest Norway in potential violation of security protocols, newspaper Stavanger Aftenblad reported.
Local police were not immediately available for comment.
The Norwegian military Home Guard has been posted at Kaarstoe and other major energy export facilities since authorities boosted security at Norwegian oil and gas installations after the Sept. 26 Nord Stream leaks.
Even before the Nord Stream incidents Norway's Petroleum Safety Authority (PSA) had warned energy companies to be vigilant for unidentified drones.
Police on Thursday responded to a threat made by telephone against the Nyhamna gas plant, which alongside Kaarstoe and a handful of other Norwegian sites rank among Europe's largest energy export facilities.
Norway is now Europe's largest gas supplier after a sharp reduction in flows from Russia.