Climate activists blockaded the London Stock Exchange by gluing themselves across the entrances.
Protesters from Extinction Rebellion attached themselves to walls and to each other at the financial centre in the City of London.
A group also climbed on to a Docklands Light Railway (DLR) train at Canary Wharf and held up banners.
Protesters at both locations have been removed, but police warned of disruption throughout the day.
Elsewhere in the City, temporary road blocks have been set up in by activists at Bank and Southwark Bridge.
Extinction Rebellion is urging the government to “tell the truth” about the scale of the climate crisis, it wants the UK to reduce carbon emissions to net zero by 2025 and it wants a Citizens’ Assembly to oversee the changes needed to achieve that goal.
More than 1,000 people have been arrested since the protests began on 15 April.
The group had previously said it would end its action later in the day, having previously blocked sites including Parliament Square and Waterloo Bridge.
Extinction Rebellion said protesters would spend the day focusing on the financial industry “and the corrosive impacts of the financial sector on the world we live in”.
The 13 activists who blockaded the stock exchange wore LED signs reading “Climate emergency”, “Tell the truth” and “You can’t eat money”.
One protester, Adam Woodall, said they had targeted the building because “people are making millions, even billions of pounds out of trading ecological destruction”.
The group was removed by police officers and transferred to police vans.
The London Stock Exchange said markets were all open as normal in spite of the action.
Four people were standing on top of the DLR train holding signs saying “Business as usual = death” and “Don’t jail the canaries”. Another activist glued herself to a carriage.
Services were able to continue on the DLR, but there were minor delays between Bank and Stratford/Lewisham.
Officers from British Transport Police used ropes, harnesses and ladders to remove the protesters.
Five people had been arrested on suspicion of obstructing the railway, the force said.
As of Wednesday evening, a total of 1,088 people had been arrested – with 69 of those charged in connection with the protest, the Met Police said.
Extinction Rebellion protesters also remain at Marble Arch, although no roads have been blocked there.
Meanwhile, Dame Emma Thompson, who joined the activists on Saturday, has defended flying from Los Angeles to London to take part.
The actress said it was “very difficult to do my job without occasionally flying” but she was “in the very fortunate position of being able to offset my carbon footprint”.
The Hollywood star added that people are “all going to have to fly less” as “the future of this planet is at stake”.
More than 10,000 officers have been deployed during the action.
Mayor of London Sadiq Khan said the protests had been a “huge challenge for our over-stretched and under-resourced Metropolitan Police”.
The group has said it would hold a “closing ceremony” at Speakers’ Corner in Hyde Park at 17:00 BST, but warned that the public should expect more action “very soon”.