Two women have been arrested after climate change protesters attacked the Royal Bank of Scotland's (RBS) Edinburgh headquarters on Sunday.
More than 100 protesters took part in the action, which also involved an oil-like substance being thrown at the building and windows being smashed.
The protest comes in response to RBS's investment in oil industry developments around the world.
It comes hours before activists begin a day of "mass action" against the bank.
RBS said the safety of its staff and customers was a priority and it would be putting security measures in place on Monday.
Lothian and Borders Police said Sunday's incident happened at about 1700 BST.
Protesters began setting up the five day Camp for Climate Change in an open area close to the building in Gogarburn on Thursday.
The activists claim the bank's financing of such oil industry developments could be dangerous for the environment.
Campaigners bearing a banner reading "Greedy pigs, bankrolling the climate crisis" tried to enter the bank's headquarters on Sunday but were stopped by officers.
Shaun Caulfield, who took part in the attempted raid, said: "RBS is one of the biggest climate criminals in the UK.
"People are angry that bankers are ploughing the billions that they got in the bail out into incredibly destructive fossil fuel projects around the world."
Golf balls were also apparently thrown at the building, the Press Association reported.
RBS, which is 84%-owned by the taxpayer, had said its offer to meet with the protest leaders had been declined.
RBS spokesman Michael Strachan told the BBC that there had been "an incident" but it was now a matter for the police.
He added that the company was taking measures to protect staff due to work on Monday and said: "The safety of our customers and staff is our top priority."
"RBS is taking precautionary measures for some staff by allowing them to work at alternative locations."
A spokeswoman for Lothian and Borders Police said: "Two protesters linked to the Climate Camp for Action were arrested following a disturbance within the grounds of the RBS compound at Gogarburn in Edinburgh."