Another post has highlighted that am indefinite strike by drivers on Vy trains has started today- https://striketracker.app/strikes-in-norway/eastern-norway-vy-train-drivers-strike-from-18-sep-2026
This is mainly affecting short to medium distance trains in Eastern Norway, including to Oslo Airport.
Note that a reduced service is running on most of the affected lines, although the effects may become worse. No alternative road transport is being provided to cover for cancelled trains.
Over the weekend a combination with scheduled engineering work means that Oslo to Bergen trains are also affected currently (although Myrdal to Flam is running as normal). A restricted service is running from Voss to Bergen service.
The timetable is being amended on a daily, ongoing basis.
The dispute seems to be about the ending of the dedicated Oslo Airport service, and it's assimilation into normal city and regional routes.