The non-violent grassroots climate action movement Extinction Rebellion is planning to occupy Heathrow Airport in London on Friday, the fifth consecutive day of a mass demonstration by the group.

"Tomorrow we raise the bar," leaders wrote to the group in a WhatsApp message Thursday. "We are going to shut down Heathrow."

Unconfirmed reports that Extinction Rebellion plan on shutting down Heathrow airport tomorrow. This message has been posted on official WhatsApp update groups #ExtinctionRebellion pic.twitter.com/2XGg1k5671 — Nick Codling (@ncodling) April 18, 2019

Since Monday, Extinction Rebellion has invited all who are concerned about the state of the climate to join demonstrations at London landmarks including Marble Arch, Parliament Square, Oxford Circus, and Waterloo Bridge, where they have blocked traffic.

Marble Arch has been blocked by the Extinction Rebellion protest. Everything’s quite quiet and peaceful. Maybe 1,000 people here. pic.twitter.com/2EAJNHsxPS — Patrick Kidd (@patrick_kidd) April 15, 2019

Parliament Square without motor vehicles is just wonderful. I hope that Extinction Rebellion leads to wider action on climate change, but at the very least let's make this permanent. pic.twitter.com/Bq4TDL75zS — James (@JamesBlurbs) April 18, 2019

Onlookers praised the demonstrators' commitment to non-violent protest. At least 460 demonstrators had been arrested as of Thursday evening, and police continued to make arrests at Parliament Square.

On Thursday, three protesters were denied bail and sent to jail for a month, pending their upcoming trial in May. Cathy Eastburn, Mark Ovland, and Luke Watson had been arrested the day before for climbing on top of a train in East London. The same day, demonstrators had superglued themselves to train cars at Canary Wharf station, with Extinction Rebellion arguing that disrupting and inconveniencing the population may be the only way to force the U.K. to take meaningful action against the climate crisis.

Two protesters from Extinction Rebellion staged a protest on the roof of a DLR train at Canary Wharf station. The protesters, a man and a woman, said they were staging a "peaceful protest", and were planning to glue themselves to the train. pic.twitter.com/eXzwfQRuKz SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— ITV London (@itvlondon) April 17, 2019

At the Marble Arch, actress and activist Emma Thompson called on the British government to take action on Thursday as she asked Britons to join the demonstrations.

"We will occupy until you take action because that is the only way we are going to save our planet," Thompson said. "We have to be here, we have to do this. It's hard, it's inconvenient for people sometimes, but it's much more inconvenient to leave a planet that's so completely destroyed that our grandchildren will be up against things that we cannot even imagine."

British actress, Emma Thompson, has called on the public to 'come and join' the #ExtinctionRebellion protest in London. Find the latest updates on the protest here: https://t.co/O5pV2tPtr9 pic.twitter.com/VcfZYGEcqb — Sky News (@SkyNews) April 18, 2019

Environment Secretary Michael Gove said Thursday that the government is taking into account Extinction Rebellion's manifesto, which demands a net zero carbon emission economy by 2025 and an official declaration that the world is facing a climate emergency.

But Home Secretary Sajid Javid called on police to respond to the planned Heathrow protest with "the full force of the law" on Friday.

Extinction Rebellion quoted natural historian David Attenborough in its official statement on the planned Heathrow action.

"We are facing a manmade disaster on a global scale," the group wrote. "We're running out of time but there's still hope…If we better understand the threat we face, the more likely it is that we can avoid such a catastrophic future."