A plane returned to New York after suspicious wires in plastic straws were found in a toilet cubicle. 

The Delta Airlines Boeing 767 had 206 people on board to Madrid. At the airport bomb technicians searched the aircraft after its return but no explosives were found.

The plane landed safely at John F Kennedy airport shortly after 9:30 p.m. E.T., the airline confirmed to The Guardian.

The airline said in a statement that the plane turned around out of an "abundance of caution."

Police spokesman Paul Browne said that two wires inside small plastic straws were found, one in the sink and one in the toilet. It is still not clear whether a flight attendant or an air marshal made the discovery. The source of wire too is uncertain.

Among the passengers withheld, one was a woman from Argentina who reported trouble breathing around the time of the discovery.

The other was a man believed to be the last person to use the bathroom before the wires were found.

Police confirmed that the investigation is on.