A Delta Airlines plane had to return to New York after suspicious wires in plastic straws were found in the bathroom.
The Madrid-bound plane was carrying 206 people when the discovery was made, and landed safely back at John F Kennedy airport out of an "abundance of caution".
According to the Guardian, bomb technicians searched the aircraft when it landed but found no evidence of explosives.
Police spokesman Paul Browne said two wires inside plastic straws were found, one in the sink, and one in the toilet.
Two passengers were questioned following the discovery.
One was an Argentinian woman who reported trouble breathing around the time of the discovery, and another was a man believed to the be last person to have used the bathroom before the wires were found.
The wires were found by a federal air marshal, and the plane was met by a Port Authority Police SWAT team that carried out a heavy weapon entry onto the flight because the pilot had radioed to say there was a woman on board who might be part of a terror team.
According to ABC News, passengers were taken off the flight in a "controlled evacuation," and were held in a terminal for questioning.
The investigation continues.