Police are searching for a man who forced Betty Davis, a 73-year-old grandmother, to rob an Arkansas bank while holding her hostage and threatening her with a bomb.

Davis told police that a man was holding her husband and her captive in their home before strapping a device described to her as a bomb to her ankle and forcing her to rob Arvest Bank in Fayetteville, Ark.

Authorities said Davis told employees at the bank about the supposed bomb strapped to her ankle while everyone from the building was safely evacuated. The man reportedly threatened her to rob the bank using the bomb as leverage.

He showed her a detonator and said: 'All I've got to do is push this button if you don't do it right,' Davis' granddaughter Carly Geanolous told Little Rock's 5News. She's a really brave woman.

A bomb squad arrived to remove the device from Davis' leg and is testing it to determine whether or not it was dangerous.

According to The Associated Press, police then went to the couple's home where they were being held captive to find the husband tied up, unharmed. The couple's pickup truck was found several miles away, abandoned.

Davis said the suspect was a white male wearing blue jeans, a mask and carrying a gun. Other details are unclear while police investigate.

Police spokesman Sgt. Craig Stout told the Arkansas Democrat-Gazette that Davis was cooperative and didn't show any signs of deception.

The evidence we have supports the witness statements so far, Washington County sheriff's Lt. Emily Augustine said on Monday.