Activists are barricading doorways and smearing red paint on buildings as London was hit by protest chaos today.
Members of Extinction Rebellion blocked entrances to major insurance marketplace Lloyd's of London with superglue, bike locks and chains.
The climate protesters are aiming to stop staff entering to close the business for at least a day amid demands it stops insuring fossil fuels projects.
Around 60 people from the eco-group are said to be at the site in the capital.
Others have scaled the outside of the building and unfurled banners, reading "End Fossil Fuels Now" and "Insure Climate Justice".
Meanwhile, demonstrators from Palestine Action shut down the London headquarters of Israel's largest arms company, Elbit Systems.
The activists smeared red paint across the building and the pavement outside it, before laying down a sign which read: "Dismantle Apartheid".
A spokesman for XR said today that staff already inside the Lloyd's of London building were allowed to leave before they began.
Clare Walmsley, a spokesperson from XR, said: “We’re here to demand an end to all new fossil fuel investments and insurance.
“By underwriting the world’s most deadly fossil fuel projects, they are creating climate chaos – floods, famine, wildfires and death.
“Insuring new oil and gas projects in the North Sea will do nothing to solve the cost of living crisis either. Instead, it locks us into a system that’s already pushing millions into poverty.”
Employees arriving today found the building closed and handed notes by activists.
They read: “As a fellow human being are you happy to help him take us down this highly dangerous path?
“As a Lloyd’s professional, do you think it makes long-term business sense to double down on a doomed sector? If not, we invite you to speak up.
“We also invite you to whistle-blow.”
The event is part of what the group has dubbed the April Rebellion, amid 10 days of ongoing disruption across the UK from Extinction Rebellion and the Just Stop Oil coalition
Police said it is "aware of groups of protesters at Liverpool Street Station and the Lloyd's building on Lime Street" and that officers are at the scene.
Palestine Action wrote on Twitter: "Palestine Action shut down the London headquarters of Israel's largest arms company, Elbit Systems. Activists have doused the site in red paint, exposing Elbit and its criminal trade.
"Since our very first action here in July 2020, we've consistently turned up the heat for Israel's weapon dealers.
"When Israel's weapons are made on your doorstep, the only thing to do is occupy their doorstep."
The action comes after activists from Just Stop Oil and Extinction Rebellion caused Tower Bridge to be closed for several hours last Friday morning.
Police were called to the bridge after protesters occupied the famous landmark and unveiled a green banner with black writing reading: "End fossil fuels now".
At the start of the month activists from Just Stop Oil and Extinction Rebellion blocked the entrance of 10 oil terminals in the UK , including in London and Birmingham.
Police forces scrambled officers to the protests, with people in high vis jackets pictured sat in front of lorries trying to leave the affected sites, while others climbed on top of tankers.
An XR spokesman said at the time: “The government is making a choice to continue its addiction to fossil fuels as war wages in Ukraine , instead of accelerating the transition to a renewable led future.
"Just a few months on from the “last chance” of COP26, Boris Johnson now claims the current crisis demands a “climate change pass.”
”All of this is taking place despite recent polling showing that the UK public wants climate action now in face of the energy crisis.”
Lloyds has been contacted for comment.
