The official said a bomb threat assessment committee (BTAC) is undertaking sanitisation drills on the flight and all 248 passengers and 11 crew members have been de-boarded.
A call threatening to bring down the plane was received at the Mumbai airport at about 2:45 pm, after which the flight was grounded.
The CISF and other security agencies are on the job, along with canine and bomb disposal squads, he said.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.