Police were called at 11.15am this morning (Thursday) to Long Street in Middleton, to reports a man was armed and making threats in a bank.
The man then stole a quantity of cash from Barclays Bank before making off on foot.
Enquiries are ongoing.
Detective Inspector Matthew Hamer said: "A man entered the bank with a note and making threats, and demanding money - he then made off with a quantity of cash.
"He is described as a white male, wearing dark grey cargo pants, black body warmer, long-sleeved black top, black woolly hat, blue surgical mask and an orange high-visibility jacket."
Anyone with information should contact Rochdale CID on 0161 856 4668, the independent charity Crimestoppers, anonymously, on 0800 555 111 or make a report via the GMP website, quoting 1091-01042021.
