A Jet Airways Mumbai-New Delhi flight was diverted to Ahmedabad shortly after some "security issues" were detected onboard early on Monday, a statement said.
The flight with 122 passengers, including seven crew, landed safely in a remote bay at the Ahmedabad airport, all passengers were disembarked and screened.
An airline official said the security issues pertained to a potential hijack and bomb threat.
The pilot alerted Ahmedabad airport authorities about the threat, the official said
The Boeing 737-900 flight 9W-339 had departed from Mumbai around 2.55 a.m. and after diversion, landed in Ahmedabad around 3.45 a.m.
The Jet Airways statement said the flight was diverted following "declaration of an emergency as per established security procedures, due to the detection of an onboard security threat".
"We are extending full cooperation to the security agencies who are investigating the matter and are not in a position to comment further at this stage," it said.
The police and other security agencies are making further enquiries in the matter in Ahmedabad while the airline made efforts to bring back the passengers to New Delhi as soon as possible.