An Air India flight to the United States made a precautionary landing at London's Stansted Airport on Thursday due to a bomb threat, which later turned out to be a hoax. An Air India official later told <em>Reuters</em> that the plane had to make the landing following a hoax telephone call, which was made to Mumbai airport. The official said the plane was still grounded in London but that there was no security threat on board. British fighter jets were authorised to travel at supersonic speeds to intercept and escort the flight in to land at London Stansted Airport, the UK Ministry of Defence said in a statement. Flight AI 191 to Newark International Airport, an airport in New Jersey serving New York City, took off from Mumbai International Airport on Thursday morning but made an emergency landing at approximately 9.50am UK time. London's Stansted Airport closed to allow the Boeing 777-337 to land but has since reopened. The Air India flight was left at an "isolated stand away from the normal airport operations," the airport said. The flight was diverted to Stansted Airport, to the north east of London, at around 9.50am local time, Essex Police said. "The plane is currently at the airport and officers are making enquiries."