Extinction Rebellion protesters have blocked Tower Bridge in London with a van and caravan, the Metropolitan Police said.
The force said on Twitter "officers were on the scene almost immediately" and are working with the City of London Police to get traffic moving.
"Activists are also laying on the junction north of Tower Bridge, this is causing further disruption," the force added.
Police confirmed that 11 people were arrested during Monday's protests, adding to the 34 people who were held on Sunday.
Extinction Rebellion activists and its affiliated groups began two weeks of climate protests in London last week to "target the root cause of the climate and ecological crisis", calling on the government to halt all new fossil fuel investment immediately.
Guildhall was covered in red paint on Friday by Extinction Rebellion protesters, who said they aimed to "highlight the blood-soaked profiteering of our financial system".
The building was described as "the administrative and ceremonial heart of the corporation of the City of London" and "the symbolic and actual centre of the system that is killing us".
The action was part of a "Blood Money" march, in which protesters wearing business suits and masks held signs saying "fossil fuel finance is killing the Earth" and "the financial industry is bleeding the Earth dry".
On Saturday, there was further disruption as hundreds of activists stopped traffic as part of an animal rights protest.
Almost 500 people gathered at Smithfield Market - the largest wholesale meat market in the UK - to hold a rally with speeches before parading through the city.
Animal Rebellion, which is an offshoot of Extinction Rebellion, organised the protest with Camp Beagle, a group calling for the release of beagle dogs at MBR Acres in Huntingdon, Cambridgeshire, which rears dogs specifically for animal research.
The campaigners blocked off Blackfriars Bridge, according to police, before moving on to other locations as part of a two-mile animal rights march.
Sky News has launched the first daily prime time news show dedicated to climate change.
The Daily Climate Show is broadcast at 6.30pm and 9.30pm Monday to Friday on Sky News, the Sky News website and app, on YouTube and Twitter.
Hosted by Anna Jones, it follows Sky News correspondents as they investigate how global warming is changing our landscape and how we all live our lives.
The show also highlights solutions to the crisis and how small changes can make a big difference.