The 20-year-old activist, who has become a key face of the movement to fight climate change, was taken away by two police officers and put into the back of a police van outside the Energy Intelligence Forum.
Several hundred protestors gathered by the InterContinental London Park Lane hotel during the "Oily Money Out" demonstration, organised by pressure groups Fossil Free London and Greenpeace, blocking all entrances to the venue. "It has been clear for decades that the fossil fuel industries were well aware of the consequences of their business models, and yet, they have done nothing.
"I've got six grandchildren. I have nightmares about the future for them," protestor Doro Marden told AFP.