The unidentified man was wearing boots with apparently hidden compartments and a watch that contained switches, wires and fuses that could be used to make a bomb, investigators said.
KGO-TV said the man was detained Thursday night at Oakland International Airport while trying to get on a flight to Southern California where he lives.
The suspect told officers the odd watch was merely an art piece.
A bomb squad responded to the scene and declared the situation to be safe.
Notable deaths of 2014 [PHOTOS]