It happened Tuesday afternoon at the Tensas State Bank in St. Joseph, La., southeast of Monroe.
Louisiana State Police say the man was armed with some type of automatic weapon. Superintendent Mike Edmonson says the FBI is on the way and a state police negotiator was on the scene.
Edmonson says authorities believe the three hostages are bank employees. It is unclear whether any customers were in the bank.
Copyright 2013 The Associated Press.