The robber showed a teller a threatening note demanding cash at 1:58 p.m. at 131 Portion Rd., police said.
The teller handed over the cash, no one was hurt, and the robber fled on foot.
There has been no arrest in the case. A police spokesman declined to say how much cash the robber got or any other details.
A woman who answered the phone at the bank declined to comment or give her name.