Environment campaigners blocked a second road across the River Thames in London on the fourth day of a protest that’s disrupted car, bus and train travel for hundreds of thousands of people in the U.K. capital.

Dozens of demonstrators halted traffic on Vauxhall Bridge on Thursday morning, according to a Twitter post from Transport for London, while Waterloo Bridge, the city’s busiest river crossing, has been closed since Monday after people chained and glued themselves beneath a truck.

So-called Extinction Rebellion activists have also blocked Parliament Square and junctions at Marble Arch and Oxford Circus, and say the protest will go on through next week at least. Police have made more than 400 arrests, including three people who pleaded not guilty to obstruction after attaching themselves to a Docklands Light Railway train in the Canary Wharf financial district.

Vauxhall Bridge links the south bank of the Thames near the headquarters of Britain’s MI6 Secret Intelligence Service and the new U.S. Embassy with the Pimlico district close to the Tate Britain art gallery and a number of government buildings.

Extinction Rebellion is demanding that the U.K. acknowledge the “crisis” posed by global warming, enact legally binding policies to reduce net carbon emissions to zero by 2025, and form a citizens assembly to oversee changes.