Scotland Yard said in a statement: “Officers are responding to a demonstration in London Bridge where protesters have assembled and are blocking the road.
“We are currently assessing the situation working to keep disruption in the area to a minimum.
“Officers are on scene actively engaging with those assembled at London Bridge. Specially trained officers are working to safely remove those who have attached themselves to the vehicle and the road.”
On Monday, Extinction Rebellion activists had used a caravan to block Tower Bridge which led to 11 people being arrested.
The London Bridge protest came as members of the affiliated Animal Rebellion group blockaded the UK’s largest dairy factory, which is operated by the company Arla.
Around 50 activists arrived at the site in Aylesbury, Buckinghamshire at 5am to erect two bamboo towers in front of the entrance and exit of the site.
A spokesman for Arla said it had worked with police to limit the impact of the action and that the morning shift changeover had been completed as normal, while production and transportation continued using its other 10 sites.
The demonstrations form part of a fortnight of Extinction Rebellion action which is intended to persuade the Government to immediately stop all investment in fossil fuels.
Extinction Rebellion London Bridge protest, in pictures