The Commonwealth Bank's ANU branch almost closed on Thursday afternoon amid "safety concerns" as a group of students protesting the bank's investment in coal projects called on fellow students to close their accounts.
Up to 40 young people armed with placards gathered outside the branch during the university's orientation week, calling on the Commonwealth Bank to divest from projects harming the environment.
Fossil Free ANU spokeswoman Claire Gardner said a number of students had already closed their bank accounts and another 60 had given the bank notice they would close their accounts unless it ended its investment in coal projects.
She estimated about 100 people had passed through the protest during the afternoon.
"Ultimately, we want CommBank not to invest in Queensland coal ports and coalmines and would like to see the Great Barrier Reef saved and Australia taking more action on climate change," she said.
"On a more local level, it's raising awareness – we've received a very positive response so far."
Ms Gardner said about five students were lining up inside the branch to close their accounts when the branch suddenly closed about 2pm, after an earlier request students move away from the bank and a warning of a call to police.
"While we were waiting in line they declared it was an emergency situation and the bank had to close and we had to vacate immediately," she said.
"It was a slight over-reaction to what we were doing. We inferred they weren't very happy about us outside.
"CommBank's reaction today shows our message is something they don't want their customers to hear."
A Commonwealth Bank spokesman said the bank limited its services temporarily Thursday afternoon.
"The Commonwealth Bank ANU branch did operate with limited service for a short period this afternoon due to staff and customer safety concerns, but is again fully operational," he said about 4pm.
The student protest, which involved a barbecue and speeches, followed a broader divestment protest calling for the big four banks to stop supporting fossil fuel projects in the city in October.
Greens MLA Shane Rattenbury, who was among Thursday's speakers, said Australia's "Big 4" banks had loaned almost $19 billion to coal and gas projects since 2008.
"We need to communicate to the banks that this is not good enough and, as consumers, the best way to do so is to vote with our feet," he said.
"I have personally made the decision to close my accounts with Commonwealth Bank, and move to a bank that takes tackling climate change more seriously. I encourage others to do the same."