A Northern Rock branch in Glasgow city centre closed with 200 people packed inside as customers rushed to withdraw money from their accounts.
Customers packed into the bank's Glasgow branch
The situation occurred after panic set in around the UK when the lender asked the Bank of England for emergency help.
The bank closed its doors in St Enoch Square just before noon with the customers still inside.
Scores of people were also queuing in the rain outside Northern Rock's branch in Castle Street, Edinburgh.
One customer turned up at the Glasgow branch at 1150 BST hoping to withdraw £20,000 of savings but was told by staff she could not come in.
The woman, in her 50s, said: "I am furious. There are 200 people inside and they are not letting us in.
"I have come down here especially and told them we are their customers."
Another customer arrived to check on the progress of a £137,000 transfer she ordered on Friday.
"I was hoping it would have been done by now, but it hasn't come through," she said.
"I'll have to wait until Monday.
"The staff have been under a lot of pressure but they have been very kind."