The 20-year-old Swedish activist could be seen smiling as she was detained by officers and led to a waiting police van after joining a protest outside the Energy Intelligence Forum (EIF) - formerly the Oil and Money conference - at the Intercontinental Hotel Park Lane. In footage shared on social media, officers could be seen frogmarching the campaigner to the van as other protesters were told to stand back. The Met Police said it had arrested 21 protesters today. Fossil Free London, which organised the demo, said Thunberg was arrested while linking arms and changing with other activists; she was reportedly taken to Wandsworth police station.