The woman -- whose name was not disclosed -- told investigators the two men abducted her Tuesday night and then took her to the Bank of America branch where she works with what they told her was an explosive device taped to her midsection, KABC-TV, Los Angeles, reported.
The gunmen -- wearing ski masks -- took the woman to the bank around 8:30 a.m. PDT Wednesday and waited outside while she went inside to remove money from the vault.
LA County Sheriff's Department Capt. Mike Parker said the woman dumped the money outside the bank.
"While she was inside the bank, there were other employees present," Parker said. "She explained to them what was happened."
The robbers fled the scene with undisclosed amount of money.
The bomb squad responded to the scene, removed the device from the woman's body, and used a remote-controlled robot to detonate it, ABC News reported.
The Los Angeles Times said the device appeared to be a pipe bomb.
Parker provided no details on how the woman was kidnapped. He said she is not suspected of involvement in a plan to rob the bank, the Times reported.