"The climate and emissions impact of burning (the oil and gas from the fields) has not been sufficiently studied or evaluated," the court said, ruling in favour of the Scandinavian branch of Greenpeace and the Nature and Youth environmental group.

The two groups filed the case in 2023 against the permits for the Tyrving, Breidablikk and Yggdrasil offshore fields, saying work there had been approved before environmental impact studies had been carried out.

A lower court had already ruled in their favour in January 2024, prompting an appeal by the Norwegian energy ministry, which argued there were no grounds to halt the projects.

Sigrid Hoddevik Losnegard, president of Nature and Youth, called the ruling "a victory for us and for our future".

"The fight for the climate is really taken seriously," she said in a statement. "Now we expect political leaders to follow this decision and put an end to these oilfields once and for all."

Many climate activists say Norway, the main producer of oil and gas in Western Europe, is profiting from their sales even though fossil fuel use is contributing to global warming.