Screeners at Washington Dulles International Airport stopped an 83-year-old woman after an X-ray showed that she was carrying a cane that concealed a sword.

The Transportation Security Administration said the woman had no idea that her walking stick was also a weapon.

TSA spokeswoman Lisa Farbstein said it's not uncommon for people to unwittingly carry canes that conceal weapons. The agency sent out an advisory Wednesday suggesting passengers with canes try to unscrew the top before heading to the airport, just in case.

In Monday's incident, the woman was allowed to board her flight without the cane and did not face charges.