Bank robbers in Miami kidnapped a teller from his home, strapped explosives on him and forced him Friday to demand an undisclosed sum of money from the branch where he works, in what an FBI agent called a most unusual bank heist.

The successful robbery -- three suspects made off with the cash in a car -- included at one point some hostages and police swat teams surrounding the Bank of America branch in Miami's Coral Gables neighborhood, police said.

The bank teller, Diego Uscamayta, was freed from his explosive-laced vest by police after he handed the money over to the robbers.

The Federal Bureau of Investigation's Miami chief Dena Choucair said Uscamayta was being questioned to gather clues on the "unusual" heist and the bank robbers.

He said the teller was kidnapped late Thursday at his home by three gunmen and was threatened with being blown up if he did not follow their instructions.

"They sent him inside and stayed outside... They said, 'We have a triggering device. Get as much money as you can and bring it out to us,''' Coral Gables Police Chief Richard Naue told reporters.