Greta Thunberg detained by Norway police during demonstration

The campaigners are demanding the removal of wind turbines from reindeer pastures on Sami Indigenous land in central Norway.

They have in recent days blocked access to some government buildings, putting the centre-left minority governmenton a crisis footingand prompting Energy Minister Terje Aasland to call off an official visit to Britain.

Thunberg, holding a red, blue, yellow and green Sami flag, was lifted and carried away by police officers while hundreds of demonstrators chanted slogans.

Norway's supreme court in 2021 ruled that two wind farms at Fosen violated Sami rights under international conventions, but the turbines remain in operation more than 16 months later.

Thunberg, for many a global standard-bearer of the campaign to end the world's reliance on carbon-based energy, was later released along with other activists who had also been detained.

She joined the protests in Oslo on Monday. Its supporters argue that a transition to green energy should not come at the expense of Sami rights.

Reindeer herders say the sight and sound of the giant wind power machinery frighten their animals and disrupt age-old traditions.

The energy ministry has said the turbines present a legal quandary despite the supreme court ruling and is hoping to find a compromise, but that it could take another year to make a new decision in the Fosen case.