A door of the plane being opened after it returned to Amsterdam. (Reuters)

Frantic relatives of passengers aboard Northwest Flight NW 42 converged at Mumbai’s Chhatrapati Shivaji International Airport after word spread that the plane had been escorted back to Amsterdam.

“I am worried sick. My 73-year-old ailing father is on the flight. He is on his way home after visiting my sister in the US,” said Yogesh Devpade, an architect, who was waiting at the Mumbai airport to gather information about the plane.

In a statement emailed to The Telegraph, Northwest said the flight returned to Amsterdam when “a couple of passengers displayed behaviour of concern”.

The airline said the flight has been cancelled for the day but it is expected to reach tomorrow night. Passengers are being accommodated at local hotels, it added.