Earlier police sources told Interfax news agency that the man entered the branch of Moscow Credit Bank at 8.40 pm on Wednesday evening, holding what appeared to be a pistol or convincing replica, and instructed cashiers to empty the cash vaults.
The staff pressed the panic button, at which point the gunman barricaded himself inside one of the offices, with four clients and two members of staff remaining on the premises.
The hostage taker then relayed the message that they would not be set free, until he was given the money inside the branch.
"He was in his 20s, and seemed in control. He didn't say much other than his demands, and later he let us go voluntarily," one of the hostages told Life News.