Many Royal Bank of Scotland staff have been advised to work from home today as climate activists target its headquarters.
Protesters have been gathering in their hundreds at the RBS building outside Edinburgh ahead of a planned day of action against the banking giant today.
The Camp for Climate Action has accused RBS of using taxpayers' money to prop up fossil fuel companies who they say are destroying the planet.
RBS is almost wholly owned by the Government, which has an 84% stake.
It is understood there were two arrests when more than a hundred demonstrators dressed in white biohazard suits breached police lines at the Gogarburn HQ at around 5pm yesterday.
Considerable damage was said to have been done to the building, with several windows smashed.
On Friday, a woman was arrested after entering the office and gluing herself to a desk.
RBS said some staff would work away from the HQ as a "sensible security measure".
A spokesman said: "We have provided some alternative locations for staff where appropriate.
"We are constantly reviewing the situation and doing everything possible to protect the safety of our employees, customers and the general public."
Protesters began setting up camp in a field behind the headquarters on Thursday.
An office, medical tent and compost toilets have been erected at the site.
A day of action is planned for today before the camp moves on tomorrow.
Activist Shaun Caulfield said last night: "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."
RBS said it provided support for businesses working across many industries, reflecting the make-up of society and the economy.
The spokesman said: "Just as society as a whole has to make a transition to renewable energy sources, so will banks like RBS.
"In fact in recent years RBS has been one of the most active banks in the world in providing funding for renewable energy projects.
"Therefore, while we understand the protesters' intent and publicity tactics, we clearly cannot agree with their decision to target RBS."