A Norweigan court on Friday ordered a 50-year-old Russian national held in custody for two weeks as he admitted to flying two drones over the country, potentially over critical energy infrastructure.
In recent weeks, there have been numerous drone sightings near the country's offshore oil and gas platforms.
Security has been ratcheted up following explosions that targeted gas pipelines in the Baltic Sea last month.
Authorities also seized four terabytes of data, some of it encrypted.
As European states seek to reduce reliance on Russian energy sources, Norway has become a key source of natural gas for those countries.
Last month, explosions ripped up two gas pipelines running through the Baltic Sea that had been built to bring Russian gas to Germany.
On Thursday, police responded to a threat phoned in against the Nyhamna gas plant, among Europe's largest facilities for exporting energy. »