Greenpeace protestors scaled a giant ladder outside the Palais conference centre at Cannes Lions, stepping up their disruption at the advertising festival to highlight the climate crisis.
Two protestors dressed in orange dog costumes climbed to a height of about 25 metres, using a truck ladder that they leaned against the side of the Palais, and unfurled a banner declaring, "This is fine", to mock the ad industry's work with fossil fuel energy companies.
The truck blocked all traffic on the westbound side of the Croissette, the main seaside thoroughfare at Cannes, and police were forced to close the road.
It is Greenpeace's third climate stunt at the world's biggest advertising festival after dozens of protestors, also dressed as dogs with "This is fine" placards, paddled in canoes via the sea to invade WPP's rented beach next to the Croissette on Wednesday.
On Monday evening, a Greenpeace protestor and former Cannes Lions-winning creative had interrupted the awards ceremony at the Palais.
There are high levels of security to enter the Palais with airport-style scanners.
The "This is fine" dog became a meme in 2013 after the Gunshow web comic character was condensed into an image of a dog sitting in a chair declaring "This is fine", while all around him the room burns.