The man who had kept a threat letter in a Mumbai-Delhi Jet Airways flight has been identified and he is also said to have confessed to have kept it. The man has been identified as one, Salla Birju, who had kept 'threatening note' to destabilise operations of the Jet Airways flight. A Delhi-Mumbai flight was diverted to Ahmedabad during the wee hours of Monday due to security reasons. Jet Airways flight 9W339, which took off from Mumbai at 2.55 am, landed at Ahmedabad airport at about 3.45 am. A passenger onboard said the flight was diverted to Ahmedabad citing "security reasons". A security personnel at Ahmedabad airport said the flight was diverted as a threat letter was found.