Kajal Patel, a worker at Rust Avenue Superette across the road from the bank, said an ANZ bank staff member came into the store just after 9.30am asking to urgently use a phone.
Patel said the worker was obviously stressed but she was unable to question the woman because the superette had other customers waiting to be served, so she simply lent her cellphone to the bank worker.
An ANZ spokeswoman said the bank was relieved no one was harmed during the incident.
“The safety of our staff and customers are of utmost importance … ANZ staff are receiving counselling and other support where required.
“As this is now a police matter, we’re not able to provide any further information,” the spokeswoman said.
A reporter on the scene said customers were being turned away and officers wearing vests were seen entering the branch.