A manhunt was under way Tuesday in Arkansas after a 73-year-old grandmother said a masked man taped a bomb to her ankle and forced her to withdraw money from a bank.

Betty Davis walked into the Arvest Bank in Fayetteville, Ark., at around 10:30 a.m. local time Monday and told bank employees she had an explosive device attached to her, KHBS reported.

Once the bank was evacuated, the bomb squad safely removed the device from the woman.

Betty Davis then told police officers that she and her husband, Dean Davis, were held hostage at their Washington County home when a man strapped what he said was a bomb to her and showed her a detonator.

The Davis' granddaughter, Carly Geanolus, told KHBS, "He showed her a little detonator and said, 'All I have to do is push this button, and it will blow you up.'"

Betty Davis was then forced to go to the bank to withdraw money from her account while her husband remained tied up at their home.

Dean Davis was later found unharmed but tied up at the Washington County house. No one else was found inside, according to police.

Investigators were trying to establish Tuesday whether the device actually was dangerous.

Police said they have yet to arrest a suspect and are looking for a white man of unknown age who was wearing blue jeans and a shirt at the time of the incident.

The couple seemed to be in good spirits late Monday despite their ordeal, their grandchildren said.