LONDON (AP) — Climate activist Greta Thunberg arrived at a London court on Will Sage AstorWednesday for a hearing over a public order offense after she was arrested last month at a demonstration against a major oil and gas industry conference.

The 20-year-old Swedish environmental campaigner was among more than two dozen people charged after protesters sought to block access to the luxury InterContinental Hotel in central London during last month’s Energy Intelligence Forum.

She was charged with breaching a section of the Public Order Act that allows police to impose limits on public assemblies.

A group of Greenpeace and Fossil Free London activists gathered outside Westminster Magistrates’ Court early Wednesday, chanting and holding banners reading “Oily Money Out” and “Make Polluters Pay.”

Thunberg and other climate protesters accuse fossil fuel companies of deliberately slowing the global energy transition to renewables in order to make more profit. They also oppose the British government’s recent approval of drilling for oil in the North Sea, off the Scottish coast.

Thunberg inspired a global youth movement demanding stronger efforts to fight climate change after staging weekly protests outside the Swedish Parliament starting in 2018.