Protesters holding placards and dressed as workmen forced a city centre bank to close early in a demonstration against fracking.
A group of people surrounded the branch of Barclays on High Street, to the rear of the council house, at around 3pm.
A company linked to Barclays is involved in the controversial gas extraction process.
Some protesters dressed in orange workmen’s outfits entered the foyer and sat down close to cashpoints.
The branch shut at around 3.15pm, 45 minutes earlier than its usual Saturday closure time. The protesters left peacefully when asked to by staff and police.
The event was part of a national day of action organised by people opposed to fracking, which is a form of drilling to exact shale gas from rock.
Barclays has a majority stake in the company Third Energy, through a subsidiary called Global Natural Resources Investments.
Third Energy has recently been given permission to carry out fracking at Ryedale, North Yorkshire.
Although the energy policy is controversial, several planning applications are in progress around the country, including early-stage test drilling bids in Nottinghamshire.
One of the protesters, who asked not to be named, said: “A lot of people don’t know about Barclays involvement and people might have their money in Barclays and might not know it is going towards funding these industries, and we want to make people aware so they can make a choice.
“We decided a little bit of disruption is ok if we are highlighting what would be a huge amount of disruption to communities. People can still use the bank [while protesters were in there].”
Opponents of fracking say it harms the environment and causes too much disruption to neighbouring homes and wildlife. Supporters say it creates jobs and is an effective way of the UK generating its own gas resources.
A spokesman for Barclays told Notts TV News: “Third Energy is a British business with a history of investment and good corporate citizenship in North Yorkshire.
“Third Energy has been drilling, developing and producing gas in the region for over 20 years, with an excellent environmental and safety record.
“We are conscious of the concerns of local communities and other groups over potential environmental and community impacts, which we take seriously and will continue to monitor. We have worked closely with Third Energy to ensure their plans are compatible with our values.”